Publications

Publications du LECD sur son site HAL

• [hal-01478434] Variation in Reproductive Success Across Captive Populations: Methodological Differences, Potential Biases and Opportunities

  28 février 2017

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• [hal-05240651] Association Between Parental Social Position and Childhood Overweight: Mediation by Lifestyle and BMI Patterns During Pregnancy

  4 septembre 2025

  In high-income countries, children born to parents with low socio-economic position (SEP) or with non-Western ethnicity are disproportionally affected by obesity as early as preschool age. We assessed how much of these associations were mediated by parental lifestyle and BMI patterns during pregnancy. We characterised 5-6 years old children with or without overweight from the French Etude Longitudinale Française depuis l'Enfance (ELFE) (n = 8584) and the Dutch Generation R birth cohorts (n = 6511). We used counterfactual mediation analyses to assess the potential mediating effect of previously identified lifestyle patterns: "high parental smoking, poor-quality maternal diet and sedentary behaviour" and "high parental body mass index and low gestational weight gain". Both patterns jointly mediated 62.8% of the association between parents' education level and childhood overweight in ELFE and 23.2% in Generation R. In Generation R, they jointly mediated 8.9% of the association between parents' geographic origin and childhood overweight. In ELFE, parents with non-Western backgrounds were less likely to follow the first pattern, resulting in a negative indirect effect. Parental lifestyle and BMI patterns during pregnancy seem key contributors to the early development of socio-economic inequalities in childhood overweight, while other yet unidentified factors may contribute to inequalities related to geographic origin. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
• [hal-04774595] Behavioural measures of child's eating temperament and their link with BMI

  8 novembre 2024

  <div><p>Rothbart's model of temperament, defined as individual differences in reactivity and self-regulation, has a strong heuristic value with applications in a wide variety of children's outcomes. Our objective was to test Rothbart's model applied to children's food behaviours and BMI outcome through behavioural measures. Our hypotheses, according to Rothbart's model, were as follows: (i) self-regulation in eating modulates appetite reactivity; (ii) appetite reactivity increases the risk of excess BMI, whereas selfregulation in eating limits this risk. One hundred and four children aged between 7 and 12 years completed four behavioural tasks to assess scores for two components of appetite reactivity (i.e. appetite arousal and appetite persistence) and two components of self-regulation in eating (i.e. self-regulation in eating without hunger and self-regulation in eating speed). Their heights and weights were measured in order to calculate their BMI-for-age. T-tests and regression analysis were used to verify our hypotheses. None of the scores of self-regulation in eating was directly associated with BMI but we observed a significant impact of self-regulation in eating without hunger on appetite arousal (p-value ¼ 0.04), together with a modest but significant association between appetite persistence and BMI (pvalue ¼ 0.02). We can thus conclude that our behavioural measures could be used for the determination of the child's eating temperament. Further studies are needed to investigate how to use these measures to improve the treatment of overweight in children.</p></div>
• [hal-04767165] Is That You I Hear? Speaker Familiarity Modulates Neural Signatures of Lexical-semantic Activation in 18-month-old Infants

  5 novembre 2024

  Abstract Developmental language studies have shown that lexical-semantic organization develops between 18 and 24 months of age in monolingual infants. In the present study, we aimed to examine whether voice familiarity facilitates lexical-semantic activation in the infant brain. We recorded the brain activity of 18-month-old, French-learning infants using EEG while they listened to taxonomically related and unrelated spoken word pairs by one voice with which they were familiarized with before the experiment, and one voice with which they were not familiarized. The ERPs were measured in response to related and unrelated target words. Our results showed an N400 effect (greater amplitudes for unrelated as opposed to related target words) over the left hemisphere, only for the familiar voice, suggesting that the voice familiarity facilitated lexical-semantic activation. For unfamiliar voices, we observed an earlier congruence effect (greater amplitudes for related than for unrelated target words). This suggests that although 18-month-olds process lexical-semantic information from unfamiliar speakers, their neural signatures of lexical-semantic processing are less mature. Our results show that even in the absence of personal relation with a speaker, familiarity with a voice augments infant lexical-semantic processing. This supports the idea that extralinguistic information plays a role in infant lexical-semantic activation.
• [hal-03677989] Development of body knowledge as measured by arm differentiation in infants: From global to local?

  25 mai 2022

  The ability to sense and use the body parts in an organized and differentiated manner is a precursor of body knowledge in infancy. To acquire this ability, the infant's brain might explore the perceptual consequences of its bodily actions. Undifferentiated body movements would gradually be replaced by more precise actions. Only a very few studies have tested this ‘global-to-local’ hypothesis, and none of them have so far been replicated. In this study, we assessed arm differentiation in 4-, 6-, and 8-month-old infants using a new contingency detection task in which infants have to detect a contingency between one of their arms’ activity and an audiovisual stimulus on a screen. We found that 4- to 8-month-old infants seem to be able to use their arms in a differentiated manner. However, surprisingly, we were not able to show a developmental trend in arm differentiation between 4 and 8 months of age.
• [hal-03130944] Sensorimotor Contingencies as a Key Drive of Development: From Babies to Robots

  4 février 2021

  Much current work in robotics focuses on the development of robots capable of autonomous unsupervised learning. An essential prerequisite for such learning to be possible is that the agent should be sensitive to the link between its actions and the consequences of its actions, called sensorimotor contingencies. This sensitivity, and more particularly its role as a key drive of development, has been widely studied by developmental psychologists. However, the results of these studies may not necessarily be accessible or intelligible to roboticians. In this paper, we review the main experimental data demonstrating the role of sensitivity to sensorimotor contingencies in infants’ acquisition of four fundamental motor and cognitive abilities: body knowledge, memory, generalization, and goal-directedness. We relate this data from developmental psychology to work in robotics, highlighting the links between these two domains of research. In the last part of the article we present a blueprint architecture demonstrating how exploitation of sensitivity to sensorimotor contingencies, combined with the notion of “goal,” allows an agent to develop new sensorimotor skills. This architecture can be used to guide the design of specific computational models, and also to possibly envisage new empirical experiments.
• [hal-03115760] Detection of sensorimotor contingencies in infants before the age of 1 year: A comprehensive review.

  19 janvier 2021

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• [hal-04389963] Can Infants Generalize Tool Use From Spoon to Rake at 18 Months?

  12 janvier 2024

  Infants start to use a spoon for self-feeding at the end of the first year of life, but usually do not use unfamiliar tools to solve problems before the age of 2 years. We investigated to what extent 18-month-old infants who are familiar with using a spoon for self-feeding are able to generalize this tool-use ability to retrieve a distant object. We tested 46 infants with different retrieval tasks, varying the tool (rake or spoon) and the target (toy or food). The tasks were presented in a priori descending order of difficulty: rake–toy condition, then either spoon–toy or rake–food, and finally spoon–food. Then, the same conditions were presented in reverse order to assess the transfer abilities from the easiest condition to the most difficult retrieval task. Spontaneously, 18-month-old infants performed the retrieval tasks better with the familiar tool, the easiest task being when the spoon was associated with food. Moreover, the transfer results show that being able to use a familiar tool in an unusual context seems necessary and sufficient for subsequent transfer to an unfamiliar tool in the unusual context, and that early and repetitive training of self-feeding with a spoon plays a positive role in later tool use.
• [hal-03919211] Premises of social cognition: Newborns are sensitive to a direct versus a faraway gaze

  2 janvier 2023

  Previous studies evidenced that already from birth, newborns can perceive differences between a direct versus an averted gaze in faces both presented in static and interactive situations. It has been hypothesized that this early sensitivity would rely on modifications of the location of the iris (i.e. the darker part of the eye) in the sclera (i.e. the white part), or that it would be an outcome of newborns’ preference for configurations of faces with the eye region being more contrasted. One question still remains: What happens when the position of the iris is not modified in the sclera, but the look is ‘faraway’, that is when the gaze is toward the newborns’ face but above his or her own eyes? In the present study, we tested the influence of a direct versus a faraway gaze (i.e., two gazes that only differed slightly in the position of the iris on the vertical axis and not on the horizontal axis) on newborns’ face recognition. The procedure was identical to that used in previous studies: using a familiarization-test procedure, we familiarized two groups of newborns (N = 32) with videos of different talking faces that were presented with either a direct or a faraway gaze. Newborns were then tested with photographs of the face seen previously and of a new one. Results evidenced that newborns looked longer at the familiar face, but only in the direct gaze condition. These results suggest that, already from birth, infants can perceive slight differences of gazes when someone is addressing to them.
• [halshs-05603536] Emotions and Bonds Within Canine Teams Working in the French Army

  27 avril 2026

  The human-dog relationships within the teams working in olfactory search within the French Armed Forces have not been investigated through an exploratory and qualitative approach. In order to expand knowledge on this professional and relational modality, semi-structured interviews were conducted with dog handlers from the French Army (n=16) performing explosive device detection and search and neutralization of individuals. Among the themes and sub-themes identified during thematic analysis, the relationships and interactions between humans and dogs emerge from canine individualities, emotions, and interpersonal bonds. The results suggest that the relationships woven between humans and dogs conducting olfactory searches in the French Army are multifaceted. The human-dog relationship in canine military teams is based on multiple characteristics such as bonds, emotions, affection, trust, communication, care, mutual support, technical learning, cooperation, interdependence, and instrumental factors. This study highlights the importance of valuing moments of closeness between the handler and the dog, outside of training and operational contexts. Furthermore, the opportunity to enhance the emotional skills of handlers is of interest in helping some to regulate their emotions, so as not to disrupt or even to assist their dog.
• [hal-04353159] Human perception of cats' communicative cues: human-cat communication goes multimodal

  19 décembre 2023

  As a central key to apprehend the human-cat relationship, the question of how humans decode the behaviours expressed by their feline companions has drawn scientists’ attention in the past decades. To this point, previous studies have not investigated humans’ understanding of cats’ communicative cues in a multimodal perspective. While communication generally implies multiple channels, the influence of signal modality as relates to human-cat communication, is still poorly understood. Therefore, the primary aim of the present study was to investigate whether people can identify cats’ communicative information using unimodal (visual or vocal) and bimodal (visual and vocal) signals. Participants (n=630) were recruited via online advertisement on social media. Each participant viewed 24 carefully operationalised video clips of cats in different emotional/behavioural conditions. Four categories were included: contentment, discontentment, solicitation (food or attention) and predatory behaviour. Clips were presented as vocal only, visual only, or bimodal (visual and vocal cues). Video clips showing a bimodal expression were identified with the highest score (91,8% of correct ratings) compared with the visual only (87,3%) and the vocal only (72,2%). All modalities considered, contentment returned the highest identification score (90,1% correct), followed by solicitation (87,2%), then predatory behaviour (86,3%). Discontentment was the most difficult behaviour to be correctly identified (71,6%). Finally, for all behavioural categories and modalities, professionals working with animals returned a higher score than lay people (86.2% vs 82.9%). Taken together, our data underline the influence of the signal modality on interspecific communication between cats and humans. Information emitted by cats as a bimodal signal (visual and vocal) is better understood by humans than visual signals. The most difficult to decipher for humans are vocal signals emitted alone. A better understanding of humans’ abilities to understand their feline counterparts, could potentially help pet owners, and animal care practitioners to optimise cat care and welfare.
• [hal-04233451] Limb Preference in Animals: New Insights into the Evolution of Manual Laterality in Hominids

  28 mai 2024

  Until the 1990s, the notion of brain lateralization—the division of labor between the two hemispheres—and its more visible behavioral manifestation, handedness, remained fiercely defined as a human specific trait. Since then, many studies have evidenced lateralized functions in a wide range of species, including both vertebrates and invertebrates. In this review, we highlight the great contribution of comparative research to the understanding of human handedness’ evolutionary and developmental pathways, by distinguishing animal forelimb asymmetries for functionally different actions—i.e., potentially depending on different hemispheric specializations. Firstly, lateralization for the manipulation of inanimate objects has been associated with genetic and ontogenetic factors, with specific brain regions’ activity, and with morphological limb specializations. These could have emerged under selective pressures notably related to the animal locomotion and social styles. Secondly, lateralization for actions directed to living targets (to self or conspecifics) seems to be in relationship with the brain lateralization for emotion processing. Thirdly, findings on primates’ hand preferences for communicative gestures accounts for a link between gestural laterality and a left-hemispheric specialization for intentional communication and language. Throughout this review, we highlight the value of functional neuroimaging and developmental approaches to shed light on the mechanisms underlying human handedness.
• [hal-01699823] Pet-directed speech draws adult dogs’ attention more efficiently than Adult-directed speech

  2 février 2018

  Humans speak to dogs using a special speech register called Pet-Directed Speech (PDS) which is very similar to Infant-Directed Speech (IDS) used by parents when talking to young infants. These two type of speech share prosodic features that are distinct from the typical Adult-Directed Speech (ADS): a high pitched voice and an increased pitch variation. So far, only one study has investigated the effect of PDS on dogs' attention. We video recorded 44 adult pet dogs and 19 puppies when listening to the same phrase enounced either in ADS or in PDS or in IDS. The phrases were previously recorded and were broadcasted via a loudspeaker placed in front of the dog. The total gaze duration of the dogs toward the loudspeaker, was used as a proxy of attention. Results show that adult dogs are significantly more attentive to PDS than to ADS and that their attention significantly increases along with the rise of the fundamental frequency of human' speech. It is likely that the exaggerated prosody of PDS is used by owners as an ostensive cue for dogs that facilitates the effectiveness of their communication, and should represent an evolutionarily determined adaptation that benefits the regulation and maintenance of their relationships. Humans speak to dogs using a special speech register called pet-directed speech (PDS) 1–4 , which is very similar to infant-directed speech (IDS) used by parents when talking to young infants. These two types of speech share prosodic and syntactic features that are distinct from the typical adult-directed speech (ADS): a high pitched voice, an increased pitch variation, short utterances, a reduced syntactic and semantic complexity, and word repetitions 1–5. PDS and IDS are also commonly described as 'happy voices' , in comparison to ADS presenting a relatively inhibited emotional content 6. Both speeches have been shown to vary according to the interaction context 7–9 , for instance PDS' prosodic features are enhanced in a positive reunion situation 9. Several studies suggest that IDS is used by humans in order to modulate infants' attention and state of arousal and to communicate their positive affect and intentions in a non-verbal way 10–14. IDS may also facilitate the emergence of language in infants by emphasizing the linguistic structure 15, 16 , for instance by using hyperaticulation of vowels 2, 3, 17 , or words repetition 18. Authors highlighted these functions in studying babies' preference for IDS toward ADS 19, 20 : infants have a longer fixation on, or turn more often the head toward visual targets that produced IDS 19. Infants also better remember and look longer at adults who have addressed them with IDS 20 , and this preference is present when IDS is produced by the infants' own mother as well as by an unfamiliar mother 12, 20. In addition, the exaggerated acoustic features of IDS elicit increased neural activity in infants, related to atten-tional processing 21. Infants also present increased social and affective responsiveness while listening to IDS compared to ADS 19. PDS and IDS may be similar because both infants and dogs are non-verbal listeners and because the affective bond between owners and dogs mirrors the human parents-infant bond. Indeed, both owners and dogs experience an important secretion of oxytocin after a brief period of cuddling 22 and a study highlighted common brain activation when mothers viewed images of both their child and dog 23. In the context of human-dog communication, there is evidence that dogs present an increased neuronal activity in the auditory cortex when listening to vocalizations with positive emotional valence compared to negative or neutral emotional valence 24. Moreover, after a greeting involving eye contact and a high pitched voice, dogs are more likely to follow the humans gaze, similarly to young children do 25, 26. Similarly, dogs are more motivated to answer a command to find hidden food in high-pitched informative than in low-pitched imperative trials 27 , suggesting that they are sensitive to the nonverbal quality of human vocal signals.
• [hal-05327470] Personality traits of aged dogs according to their cognitive status

  23 octobre 2025

  <div><p>Canine cognitive dysfunction (CCD) syndrome is a neurodegenerative condition that shares similarities with Alzheimer's disease (AD) in humans. In human studies, high neuroticism, low openness, and low extraversion have been significantly associated with AD diagnosis. Similarly, changes in dog behaviour, including alterations in personality, have been reported as common features in dogs with CCD, but no precise assessment of their changes has yet been realised. The aim of this study (based on the CaniAge cohort) was to compare characteristics of dogs with cognitive impairment (CI dogs) and non-CI dogs in a French senior dog population including owner-reported personality traits between dogs. Data were collected via an online survey, including the CADES scale (Canine Dementia Scale), the Monash Canine Personality Questionnaire, the Canine Owner-Reported Quality of Life (CORQ) assessment, and an environment questionnaire. Dogs aged of 6 years and older were included. Responses were obtained for 566 senior dogs of various breeds, with a median age of 9.86 years (Interquartile range: 8.08-11.98). Among them, 234 were classified as cognitively impaired, including 182 with mild impairment, 44 with moderate impairment, and 8 with severe impairment or dementia. Compared to non-CI dogs, CI dogs scored significantly lower on extraversion and amicability, and higher on neuroticism. After adjustment, CI dogs showed significantly lower amicability and higher neuroticism compared to non-CI dogs. This study is complementary of previous studies regarding CI-characteristics but is also the first to explore personality trait differences between CI and non-CI dogs, supporting observations previously reported in Alzheimer's disease research.</p></div>
• [hal-03861918] How’s my kitty? Acoustic parameters of cat-directed speech in human-cat interactions

  20 novembre 2022

  In Western cultures, humans tend to use a specific kind of speech when talking to their pets, characterised, from an acoustical point of view, by elevated pitch and greater pitch modulation. Pet-directed speech (PDS), which has been mainly studied in dogs, shares some acoustic features with infant-directed speech (IDS), used when talking to young children. The purpose of this study was to test the hypothesis that adult humans also modify characteristics of their voice when talking to a cat. We compared acoustic parameters of speech directed to cats (CDS) and speech directed to adult humans (ADS). In a first experiment, we compared ADS and CDS utterances of male and female participants, addressing cats through video recordings, under controlled laboratory conditions. Both men and women used a higher pitch (mean fundamental frequency, or mean F0) in CDS vs. ADS. The second experiment was conducted under conditions allowing direct cat-human interactions, in a cohort of women. Once again, mean F0 was significantly higher in CDS vs. ADS. Overall, these data confirm our hypothesis that humans change the way they speak when addressing a cat, mainly by increasing the pitch of their voice. Further research is needed to fully investigate specificities of this speech.
• [hal-04700317] Cognitive performance of grey mouse lemurs (Microcebus murinus) during a discrimination learning task: Effect of the emotional valence of stimuli

  17 septembre 2024

  Emotions are omnipresent in many animals' lives. It is a complex concept that encompasses physiological, subjective, behavioural and cognitive aspects. While the complex relationship between emotion and cognition has been well studied in humans and in some nonhuman primates, it remains rather unexplored for other nonhuman primate species, such as lemurs. In our study, we evaluated the performance of N = 48 grey mouse lemurs (Microcebus murinus) in a discrimination learning task using visual emotional stimuli. We tested whether the type of visual stimulus (positive, negative or neutral) influenced the cognitive performance of mouse lemurs. Individuals had to learn to discriminate between two platforms according to the associated visual stimuli and to jump to the target platform (leading to a reward). Our main finding was that emotional stimuli, whether positive or negative in valence, impaired cognitive performance when used as a target.<p>Specifically, the lowest success rate occurred when the target was associated with the emotional stimuli, and the highest success rate occurred when it was associated with neutral stimuli. Our results show a similar pattern to that found in other primate species and support the adaptive role of emotion. Our results also support that individual differences could be a factor impacting the relation between emotion and cognition. This study is the first to explore how emotions interfere with the cognitive abilities of a lemur species and highlights the importance of acknowledging emotion in mouse lemurs as well as studying the emotion-cognition interaction in a wider range of primate species.</p>
• [hal-01478437] Effect of Interaction Type on the Characteristics of Pet-Directed Speech in Female Dog Owners

  28 février 2017

  Recent studies focusing on the interspecific communicative interactions between humans and dogs show that owners use a special speech register when addressing their dog. This register, called pet-directed speech (PDS), has prosodic and syntactic features similar to that of infant-directed speech (IDS). While IDS prosody is known to vary according to the context of the communication with babies, we still know little about the way owners adjust acoustic and verbal PDS features according to the type of interaction with their dog. The aim of the study was therefore to explore whether the characteristics of women's speech depend on the nature of interaction with their dog. We recorded 34 adult women interacting with their dog in four conditions: before a brief separation, after reuniting, during play and while giving commands. Our results show that before separation women used a low pitch, few modulations, high intensity variations and very few affective sentences. In contrast, the reunion interactions were characterized by a very high pitch, few imperatives and a high frequency of affectionate nicknames. During play, women used mainly questions and attention-getting devices. Finally when commanding, women mainly used imperatives as well as attention-getting devices. Thus, like mothers using IDS, female owners adapt the verbal as well as the non-verbal characteristics of their PDS to the nature of the interaction with their dog, suggesting that the intended function of these vocal utterances remains to provide dogs with information about their intentions and emotions.
• [hal-05483423] Advancing Biobehavioral Research: An Overview and Update from the University of São Paulo Twin Panel

  29 janvier 2026

  Abstract The Painel USP de Gêmeos (University of São Paulo Twin Panel) is, based at the Instituto de Psicologia da Universidade de São Paulo. It was formally established in 2017 to advance research on fundamental psychological processes through twin study designs. Our relatively new registry comprises a volunteer sample of 8839 twin individuals, 70% of whom live in Brazil’s Southeast, the region with the highest twinning birth rate (10.64‰) of the country, within a national population of 213 million. Our collaborative research group has expanded to include partners from psychology, dentistry, and medicine at USP, as well as other Brazilian institutions, such as the Universidade Federal do Rio Grande do Norte, Universidade Federal da Bahia, and Universidade Federal do Espírito Santo. We are advancing biobehavioral research in Brazil through innovative methodologies, interdisciplinary collaboration, and international partnerships. All twin participants contribute to multiple studies associated with four datasets employing the same hierarchical identification system for participants and families: the Biorepository, the Physiological and Physical Repository, the Behavioral Repository, and Fonoteca Cesar Ades (FOCA). Future directions include expanding our twin registry across the five regions of Brazil, our research partnerships, promoting genetic literacy, and fostering public engagement.
• [hal-05661819] Investigating Multimodal (Visual, Acoustic, and Thermal) Ovulatory Signaling in a Non‐Human Primate Species (Cercocebus torquatus)

  18 juin 2026

  In primate species, females communicate their reproductive status through multiple sensory channels, with visual signals such as swelling size being well documented. We investigated whether thermal (swelling temperature) and auditory (acoustic structure of copulation calls) modalities are also informative about the timing of ovulation in red‐capped mangabeys ( Cercocebus torquatus ). Over 4 months, we collected standardized photographs, thermal images, audio recordings, endocrine (progesterone) and behavioral data from a captive group of six adult females and one resident male. We analyzed variation in swelling size, swelling skin temperature, and temporal and spectral parameters of female copulation calls according to the timing of ovulation ( N = 15 cycles). Swelling size, but not temperature, varied with the likelihood of ovulation. Copulation calls produced close to ovulation were hoarser, showing a lower harmonic‐to‐noise ratio and higher entropy. We found no evidence that thermal or auditory traits influenced male inspection toward females or the likelihood that they engaged in a second mating. These findings suggest that, in this population, ovulatory signaling is primarily unimodal (visual), although such a system could operate within a broader multimodal framework of female reproductive signaling. Our study, while deserving further extension, provides novel insights into the relative contribution of different modalities to ovulatory communication in non‐human primates.
• [hal-00087299] Estimating the complexity of bird song by using capture-recapture approaches from community ecology

  21 juillet 2006

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• [hal-05568101] Development of Dating Motivations During High School: Contributions of Romantic Experiences

  26 mars 2026

  Objective - Adolescent dating motivations are often considered a key issue in understanding dating and sexual behaviors. Despite their initial identification, the development of these motivations and their correlates remains understudied. The present study aimed to investigate the development of dating motivations over a 3-year period using a longitudinal design, and to explore the moderating roles of romantic experiences and current dating status. Method - French late adolescents (N = 493; 61% girls) completed a questionnaire six times over 3 years. Rooted in self-determination theory, the questionnaire assessed their amotivation for dating, intrinsic motivation (intimacy and companionship), identified regulation (pleasure and dating timetable), and external motivation (peer pressure), as well as their romantic experiences and current dating status. Results - As expected, growth models revealed an increase in identified regulation and intrinsic motivation, and a decrease in amotivation, and external motivation between the beginning and end of high school. Gender differences emerged in the developmental trajectories of these motivations: girls showed a more rapid decline in amotivation and a steeper increase in identified regulation than boys. Furthermore, the gender gap in intrinsic motivation increased across the six waves. Conclusions - Overall, the findings support the view that adolescents progressively shift toward more self-determined motivations with age-a process that appears to occur earlier in girls than in boys. Romantic experiences and current dating status hindered the decrease in amotivation and made only a small contribution to the development of other forms of regulation. Practical implications of the development of dating motivation and gender differences are discussed.
• [halshs-00193345] A naturalistic study of early lexical development: General processes and inter-individual variations in French children

  3 décembre 2007

  This study investigated early lexical development in French by analysing changes and variability in lexical production and composition of children’s spontaneous speech samples from three age groups: 1;8, 2;6 and 3;3 years (20 children in each). Analyses of general developmental changes showed that lexical productivity increased strongly between 1;8 and 2;6 and between 2;6 and 3;3. Changes in lexical composition mostly occurred between 1;8 and 2;6, indicating that the most important reorganizations are achieved by 2;6. The main changes observed (decreases in proportions of nouns and paralexical classes, and increases in proportions of predicate and grammatical classes) fit overall the developmental trajectories found for other languages, such as English and Italian. Two controversial issues were particularly examined and discussed with regard to cognitive, language-specific and methodological factors: noun-verb asynchrony and grammatical word explosion. Quantitative individual differences in lexical composition were greater at 1;8 than at 2;6 and 3;3, supporting the hypothesis that stylistic variation decreases in the course of the third year. Children’s lexical profiles were strikingly diversified at 1;8, whereas they appeared as variants of a same ‘grammatical profile’ at 2;6 and 3;3. We propose that the decline of stylistic variations reflects the impact of developmental constraints, such as the necessity for children to produce function words, which suggests that variations found in the youngest children are not determinant factors for subsequent lexical development.
• [hal-02949928] Le DLPF : un nouvel outil pour l'évaluation du développement du langage de production en français

  26 septembre 2020

  Nous présentons ici un instrument, dénommé DLPF, qui est destiné à permettre une évaluation du développement du langage de production chez les enfants français entre le début de la deuxième année et la fin de la quatrième année. C’est un instrument d’évaluation indirecte – il s’agit d’un questionnaire à faire remplir par les parents – que nous avons souhaité rendre le plus complet possible, couvrant les principales acquisitions dans les trois dimensions lexicale, grammaticale et pragmatique. Des extraits des annexes complètent la présentation. La version complète de ces annexes est disponible directement auprès des auteurs.
• [hal-04133300] Young children’s difficulties in switching from rhythm production to temporal interval production (>1 s)

  19 juin 2023

  This study examined the young children's abilities to switch from rhythm production, with short inter-tap intervals (ITIs), to temporal interval production, with long ITI (>1 s), in a sensorimotor synchronization task. Children aged 3-and 5-year-olds were given six sessions of synchronization. In a control group, they had to synchronize their ITI to an inter-stimulus interval (ISI) of 4 s. In the experimental group, they must progressively increase their ITI for one session to the next (from 0.4 to 4.0-s ISI). Our results showed that the 5-yearolds produced longer ITI that the 3-year-olds in synchronization. However, the value of ITI in the 5-year-olds never exceeded 1.5 s, with more variable ITI in the control than in the experimental group. In addition, at 5 years, boys had more difficulties than girls in changing their tapping rhythm. These results suggest a temporal window in sensorimotor synchronization, beyond which the rhythm is lost and the synchronization becomes difficult.
• [hal-04687928] Young children's difficulties in switching from rhythm production to temporal interval production (>1 s)

  4 septembre 2024

  In order to efficiently perform audio-motor coordination children must process event duration. It has recently been shown that duration processing in adults involves two distinct, or at least hierarchically interrelated, processes. The processing of durations ranging from a hundred milliseconds to around one second is well accounted for by the Scalar Timing Theory. For duration above one second, temporal processing in adults appears to be task-dependent. Performances in the range of a hundred millisecond durations are usually studied with auditory tempo tasks. In this study, we examine timing performance in children for a large range of durations, from 400 ms to 4 seconds, using the same experimental design. The procedure consists in a motor synchronization task. Overall, our results show that 5 year olds perform better than 3 year olds. However, durations greater than, 1500 ms are difficult to process, leading to increasing variability in produced intervals. Moreover, only a few children are able to produce very long duration intervals. The main finding of this study confirms the existence of a break in the region of 1500 ms when a repeated synchronization task is tested. Consistently with the adult literature, this finding suggests the existence of two duration-dependent timing processes when children have to coordinate their motor behavior to external events
• [hal-04672457] Human-dog trust and cohesion within French military canine teams

  19 août 2024

  Studies on the relationships and interactions within human-dog teams in the French Army are scarce. In order to better understand this subject, a qualitative exploratory study was undertaken by conducting semi-structured interviews with dog handlers (n = 16). The interviewees work in the French Army. They are specialized in the detection and neutralization of individuals or explosives. Thematic analysis identified different themes: trust within the team, doubts, interspecific cohesion, and care provided to the dogs. The results highlight the importance of trust within the canine team. It is conceived as a dynamic, constructed process, based on experience, and involving both members of the team. It emerges that trust arises from individual, relational, technical, and experiential factors: the bonds formed, knowledge of one’s dog, difficulties related to technical aspects, the reliability of the dog following training, and mission successes. Kindness, support, and mutual protection are also important criteria. A form of interspecific cohesion is envisaged by experienced handlers when affection, knowledge, reliability, mutual assistance, and support are present.
• [hal-05528306] A day in the life of an aged cat – Environment of old domestic cats and welfare implications

  29 avril 2026

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• [hal-05528308] Comparison of the frailty phenotype and frailty index for identifying vulnerable companion dogs

  29 avril 2026

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• [hal-05528295] Perception and use of cannabidiol (CBD) by French pet owners

  29 avril 2026

  This study explored pet owners’ perceptions and use of cannabidiol (CBD) for dogs and cats in France, examining factors associated with CBD use and attitudes toward the product. A total of 2050 pet owners completed an online survey including demographic characteristics, pet health, knowledge, and attitudes toward CBD. Findings revealed that CBD use was not widespread but remained notable, with 29 % of dog owners and 13 % of cat owners reporting administration, rates lower than those reported in countries such as the United States, Canada, or Slovenia. Use was more prevalent among younger owners and those with prior personal experience of CBD or other alternative treatments. No significant difference was observed between urban and rural residents, likely due to widespread internet access facilitating information and online purchases. A higher proportion of dogs than cats received CBD, possibly due to the greater difficulty of administering oral substances to cats. Despite its relatively limited use, owners generally held positive views of CBD’s safety and benefits. Longer durations of CBD administration were linked to higher satisfaction levels. Importantly, discussions with veterinarians were significantly associated with CBD use, and veterinary recommendation was reported as a strong motivator for purchase decisions. Behavioral issues and pain were the main reasons for CBD use across species. Limitations include potential selection bias, a strong sex imbalance that limits representativeness for male owners, and reliance on self-reported data without clinical confirmation. These findings underline the need for clearer regulations, enhanced veterinary education, and clinical trials to provide evidence-based guidance on CBD use in veterinary medicine.
• [halshs-05603528] “A Dog Handler Is not a Specialized VAB Mechanic!” To Be a Human–Dog Team Conducting Olfactory Search in the French Military

  27 avril 2026

  This study aims to investigate the relationships and interactions within French military human–canine teams conducting olfactory searches. A thematic content analysis has been carried out based on 16 interviews with handlers from the French Army. Three themes are presented, focusing on 1) canine handler, a distinct specialty; 2) missions, as the real-world for the military canine team; 3) training dogs. The relationships and interactions between humans and dogs within canine teams are partly shaped by the context of the missions, by the military institution, as well as by the particularities of dyad members. Degraded environments, risks, and death are essential determinants in the preparation and implementation of canine teams, as well as in the relationships established within the partnership.
• [hal-05363829] Lifetime evolution of vocal repertoires in a songbird, the black redstart: a longitudinal field approach

  13 novembre 2025

  Oscine songbirds learn to sing mainly by imitating conspecific adults. Song learning programs are diverse, ranging from species that can only learn during the first months of life to species that are able to learn new songs throughout their lives. There is a paucity of longitudinal studies in the field on this matter. We investigated the changes of male strophe repertoires and strophe sharing over the lifetime, in a migratory population of a territorial songbird, the black redstart, Phoenicurus ochruros, by recording colour-ringed individuals during eight consecutive breeding seasons (2015–2022). We previously described the existence of microdialects between the different territorial male clusters (2–8 individuals breed in scattered patches of buildings). Three sets of time points were used to establish the time frame and to identify the types of changes males used to modify their repertoires. Males were recorded at their arrival from migration for their first breeding season (N = 52). We also followed 40 individuals during extended periods, most often covering their whole life: 25 were recorded on multiple occasions during their first breeding season and 24 were recorded during at least two breeding seasons. Most males kept their strophe repertoires stable throughout their lifetime (2–8 years). Those who shared only a few or no strophes with their neighbours when they first established their territories (14/40) changed their repertoires through: (1) addition of shared strophes, (2) selective attrition of unshared strophes and (3) gradual modification of syllables. All the repertoire changes resulted in an increase in song sharing with neighbours. Thus, black redstarts adapt their songs to their social environment mostly during the first breeding season but also throughout their lifetime. Our results support a continuum view of song plasticity and emphasize the necessity of long-term studies in order to understand the variability of song-learning processes.
• [hal-05363846] Individual benefits of nestling begging: experimental evidence for an immediate effect, but no evidence for a delayed effect

  14 novembre 2025

  The evolutionary stability of honest signalling by offspring is thought to require that begging displays be costly, so the costs and benefits of begging—and whether they are experienced individually or by the whole brood—are crucial to understanding the evolution of begging behaviour. Begging is known to have immediate individual benefits (parents distribute more food to intensely begging individuals) and delayed brood benefits (parents increase provisioning rate to the brood), but the possibility of delayed individual benefits (previous begging affects the current distribution of food) has rarely, if ever, been researched. We did this using playback of great tit Parus major chick begging and a control sound from either side of the nest. Male parents fed chicks close to the speaker more when great tit chick begging, but not other stimuli, was played back. In contrast, there was no effect of playback at the previous visit on the chicks that male parents fed. We have thus demonstrated an immediate individual benefit to begging, but found no evidence of a delayed individual benefit in this species.
• [hal-05335666] First 1000 Days Strategies to Prevent Childhood Obesity: A Narrative Review and Recommendations From the EndObesity Consortium

  28 octobre 2025

  Childhood obesity remains a major global public health challenge, leading to significant short‐ and long‐term adverse health outcomes and imposing substantial societal costs. Recognising the critical importance of early intervention, the Horizon2020 EU‐funded JPI Consortium EndObesity has prioritised the first 1000 days of life, from preconception to 2 years of age, as a key window for obesity prevention strategies. This narrative review synthesises findings from the EndObesity Consortium, summarising evidence from large multi‐cohort studies on the influence of family‐based health behaviours in the first 1000 days on offspring obesity risk, the potential of childhood obesity prediction models in the first 1000 days, and strategies to enhance prenatal and postnatal interventions to prevent childhood obesity development. Finally, we present recommendations for research, practice, and policy to address the complex, multifaceted challenges of childhood obesity prevention in the first 1000 days.
• [hal-05249036] Evaluation of the Factorial Structures of the Canine Behavioral Assessment and Research Questionnaire (C-BARQ) in France

  1 octobre 2025

  This study aimed to evaluate the factorial structure of the French version of the C-BARQ by analyzing the behaviour of 246 dogs, based on responses from 248 participants, in order to confirm its potential applicability in France. An exploratory factor analysis (EFA) identified 13 primary factors comprising 63 items, explaining 54.1 % of the total variance and a confirmatory factor analysis (CFA) revealed a good fit with the original US model. The French version of the C-BARQ mirrors the core structure of other validated versions, confirming its cross-cultural robustness, while also highlighting certain specificities. The emergence of the combined factor "Stranger-directed aggression/fear" suggests that non-expert respondents may have difficulty distinguishing between these two dimensions. Two new factors—"Passerby-directed aggression " and "Compulsive-like behaviour"—emerged, likely reflecting the characteristics of the study sample and the inclusion of the full set of items. Other notable differences include the clustering of certain attachment-related items with those related to energy, forming a new factor labeled "Social excitability/energy," as well as the absence of the "Dog rivalry" factor due to insufficient responses. Overall, the results indicate that the French version of the C-BARQ is a valid tool for assessing canine behaviour. However, cultural, contextual, and demographic differences should be considered when interpreting the findings. This study paves the way for future research on the factors influencing perceptions of canine behaviour and on the adaptation of psychometric instruments across cultural contexts.
• [hal-05288877] Two Emotional Roots of Youths’ Earth-Friendly Career Aspirations: Eco-Anxiety and Empathy Toward Animals

  29 septembre 2025

  The present study examined the role of eco-emotions in youths’ career development. We hypothesized that eco-anxiety and empathy toward animals account for children’s and adolescents’ earth-friendly career aspirations (EFCAs). Relying on focus groups of third-to-ninth-grade French students, we used a thematic analysis to explore their view of careers that respect the earth. The main themes uncovered were used to construct a self-report EFCA scale. French third-to-ninth graders ( N = 587, 51% girls) from middle-to-high socio-economic levels participated in a survey assessing EFCA, eco-anxiety, and empathetic attitudes toward animals. The results showed that these two emotions made independent contributions to EFCAs. The EFCAs were lower in early adolescents than in children, and higher in girls than in boys. We propose that eco-emotions are adaptive and function as a “watchtower” by enhancing youths’ earth-friendly plans for their adult life. We discuss the relevance of taking EFCAs and eco-emotions into account in career counseling.
• [hal-05200672] Assessing flexibility in meaning and context in non‐human communication

  5 août 2025

  The concept of flexibility in communication is central to reconstructing the evolutionary history of language, and grappling with “contextual flexibility” in particular is pivotal to address implications for pragmatics‐first accounts of language evolution. Despite significant advances in the field, research is hindered by definitional inconsistencies and methodological gaps across modalities. We build on recent frameworks to propose further, detailed methods for studying contextual and functional variability, incorporating modality‐agnostic and standardised terminology to facilitate cross‐species comparisons. Our approach includes a detailed classification of communicative contexts and outcomes, offering practical methods to disentangle context from function and meaning. By integrating insights across behavioural ecology and comparative psychology, we aim to enhance the comparability of findings and provide a robust foundation for exploring the evolutionary trajectory of communicative flexibility and pragmatics.
• [hal-05036469] The impact of humor on infant social learning: Insights from social gaze, heart rate variability, and laughter

  19 avril 2025

  Humor is a universal aspect of human culture, serving both social and cognitive functions. This study investigates humor's influence on infant learning, focusing on physiological, behavioral, and emotional responses. Building on previous research, we examined three questions: (1) Does humor affect infants' behaviors during a social learning task, such as looking, laughing, and smiling? (2) Does humor enhance learning, and is this effect age-dependent? (3) Can arousal, measured by heart rate variability (HRV), explain the relationship between humor and learning? We tested 88 infants aged 14–22 months, exposing them to either a humorous or neutral demonstration of a tool-use task. We assessed infants’ performance after demonstration and coded social gazes and emotional reactions. We also analyzed physiological arousal indicators, namely heart rate variability (HRV), through a connected wristband. Our analyses revealed that infants exposed to humorous demonstrations showed enhanced learning compared to those in the neutral condition, independently of whether they laughed or not. This suggests that laughing does not mediate the effect of humor on learning. Additionally, infants in the humorous condition looked more at the experimenter, which could indicate increased engagement or attentional processes. Finally, our HRV analyses revealed that infants who succeeded in the task exhibited higher HRV than those who did not. This study is the first to explore the mechanisms underlying humor’s effect on infant learning, emphasizing its complexity and the need for a multidimensional approach integrating cognitive, behavioral, and physiological factors.
• [hal-04952306] Decreased risk-proneness with increasing age in equally raised and kept wolves and dogs

  17 février 2025

  A basic mechanism of domestication is the selection for fearlessness and acceptance of humans as social partners, which may affect risk-taking behavior and the ability to use humans as social support, both at the behavioural and physiological levels. We combined behavioural observations with heart rate parameters (i.e., HR and heart rate variability, HRV) in equally raised and housed wolves and dogs to assess the responses to food offered in the vicinity of a potential stressor (an unknown spinning object) with and without social support from a familiar human. Based on previous studies on neophobia in wolves and dogs, we expected dogs to be less scared of the object, approach more quickly, show less ambivalent behaviour, lower HR, and higher HRV, than wolves, especially at the presence of a human partner. However, we found that mainly age and the presence of a familiar human affected the behaviour of our subjects: older wolves and dogs were generally bolder and faster to approach the food and the familiar human’s presence increased the likelihood of taking it. HR rate parameters were affected by age and the stage of the test. Wolves and dogs showed particularly high HRs at the beginning and end of the test sessions. We conclude that in our paradigm, wolves’ and dogs’ risk-proneness varied with age, rather than species. Additionally, the presence of a familiar human increased the motivation of both, dogs and wolves to take the food.
• [hal-04531919] Human genetic data reveal contrasting demographic patterns between sedentary and nomadic populations that predate the emergence of farming

  4 avril 2024

  Demographic changes are known to leave footprints on genetic polymorphism. Together with the increased availability of large polymorphism data sets, coalescent-based methods allow inferring the past demography of populations from their present-day patterns of genetic diversity. Here, we analyzed both nuclear (20 noncoding regions) and mitochondrial (HVS-I) resequencing data to infer the demographic history of 66 African and Eurasian human populations presenting contrasting lifestyles (nomadic hunter-gatherers, nomadic herders, and sedentary farmers). This allowed us to investigate the relationship between lifestyle and demography and to address the long-standing debate about the chronology of demographic expansions and the Neolithic transition. In Africa, we inferred expansion events for farmers, but constant population sizes or contraction events for hunter-gatherers. In Eurasia, we inferred higher expansion rates for farmers than herders with HVS-I data, except in Central Asia and Korea. Although isolation and admixture processes could have impacted our demographic inferences, these processes alone seem unlikely to explain the contrasted demographic histories inferred in populations with different lifestyles. The small expansion rates or constant population sizes inferred for herders and hunter-gatherers may thus result from constraints linked to nomadism. However, autosomal data revealed contraction events for two sedentary populations in Eurasia, which may be caused by founder effects. Finally, the inferred expansions likely predated the emergence of agriculture and herding. This suggests that human populations could have started to expand in Paleolithic times, and that strong Paleolithic expansions in some populations may have ultimately favored their shift toward agriculture during the Neolithic.
• [hal-04531876] Adaptive Value of Phenological Traits in Stressful Environments: Predictions Based on Seed Production and Laboratory Natural Selection

  4 avril 2024

  Phenological traits often show variation within and among natural populations of annual plants. Nevertheless, the adaptive value of post-anthesis traits is seldom tested. In this study, we estimated the adaptive values of pre- and post-anthesis traits in two stressful environments (water stress and interspecific competition), using the selfing annual species Arabidopsis thaliana. By estimating seed production and by performing laboratory natural selection (LNS), we assessed the strength and nature (directional, disruptive and stabilizing) of selection acting on phenological traits in A. thaliana under the two tested stress conditions, each with four intensities. Both the type of stress and its intensity affected the strength and nature of selection, as did genetic constraints among phenological traits. Under water stress, both experimental approaches demonstrated directional selection for a shorter life cycle, although bolting time imposes a genetic constraint on the length of the interval between bolting and anthesis. Under interspecific competition, results from the two experimental approaches showed discrepancies. Estimation of seed production predicted directional selection toward early pre-anthesis traits and long post-anthesis periods. In contrast, the LNS approach suggested neutrality for all phenological traits. This study opens questions on adaptation in complex natural environment where many selective pressures act simultaneously.
• [hal-04495671] Directional female preference for an exaggerated male trait in canary (Serinus canaria) song

  8 mars 2024

  Motor constraints on vocal production impose a trade–off between trill rate and frequency bandwidth within birdsong. We tested whether domesticated canary (Serinus canaria) females, reared either in acoustic isolation or in aviary conditions, had a preference for broad bandwidth songs with artificially increased syllable rates. The copulation solicitation display (CSD) was used as an index of female preference. As predicted, both naive and experienced females were especially responsive to syllables with a broad bandwidth emitted at an artificially increased rate. Female preference for supernormal stimuli provide support for the honest–signalling hypothesis and our results are consistent with recent findings indicating that production of song phrases maximizing both bandwidth and syllable rate may be a reliable indicator of male physical or behavioural qualities. We suggest that female preference for vocal emissions, which simultaneously maximize these two parameters, could be a widespread pattern within songbirds.
• [hal-04495650] Parental care and brood division in a songbird, the black redstart

  8 mars 2024

  Sexual conflict over parental care can be mediated through differences in male and female overall feeding rates, brood division or both. At present, it is not clear whether post-fledging brood division occurs due to sexual conflict over parental investment or is due to bi-parental cooperation, e.g. increase offspring fitness. We provide evidence suggesting that brood division in the black redstart, Phoenicurus ochruros is due to sexual conflict. Males and females had similar feeding contributions during the nestling stage, which is common for most passerine species. After fledging, each parent showed long-term feeding preferences for particular chicks within the brood. In most cases (74%; 17/23) both parents provided care but males tended to feed less fledglings than females did and in about a quarter of cases (26%; 6/23) females fed the whole brood by themselves. The relative amount of male to female post-fledging feedings showed a significant negative relationship with the proportion of fledglings cared for exclusively by the male. These results suggest (1) a close link between the amount of parental care and brood division; (2) sexual conflict can be mediated through brood division; (3) female redstarts appear to loose this conflict more often than male redstarts, with in the extreme cases males showing post-fledging brood desertion. A literature review shows brood division to occur in at least a dozen of songbird species but male black redstarts have the lowest relative post-fledging parental investment, expressed either as feeding rates or number of chicks in care.
• [hal-04495435] In a songbird, the black redstart, parents use acoustic cues to discriminate between their different fledglings

  8 mars 2024

  Several studies on parental investment in territorial songbirds have reported the existence of brood division. This is a type of postfledging care in which each parent has long-term feeding preferences for different young within a brood, creating two family units. Recent theoretical work indicates that conflicts between individuals should select for brood division. However, little is known about the mechanisms involved in the onset and maintenance of this behavioural strategy. Given the high rate of fledglings' begging calls, we hypothesized that acoustic discrimination could explain the stability of feeding preferences at a proximate level. In a 3-year field study, we recorded the responses of parent black redstarts, Phoenicurus ochruros, a territorial songbird, to playback of the begging calls of fledglings fed by the male and by the female. Parents responded more to the calls of the fledglings that they preferentially fed. A principal component analysis of the calls suggested that parents may recognize individual offspring. To our knowledge, this study provides the first evidence that a bird can acoustically discriminate between two categories of its own offspring: those that it preferentially feeds and those fed by the other parent.
• [hal-02326174] The emergence of use of a rake-like tool: a longitudinal study in human infants

  12 janvier 2024

  We describe the results of a longitudinal study on five infants from age 12 to 20 months, presented with an out of reach toy and a rake-like tool within reach. Five conditions of spatial relationship between toy and rake were tested. Outcomes and types of behavior were analyzed. There were successes observed around 12 months in the condition of spatial contiguity between rake and toy, but these could not be interpreted as corresponding to full understanding of the use of the rake. At this age and for the following months, in the conditions involving spatial separation between rake and toy, infants' strategies fluctuated between paying attention to the toy only, exploring the rake for its own sake, and connecting rake and toy but with no apparent attempt to bring the toy closer. Only between 16 and 20 months did infants fairly suddenly start to intentionally try to bring the toy closer with the tool: at this stage the infants also became able to learn from their failures and to correct their actions, as well as to benefit from demonstration from an adult. We examine the individual differences in the pattern of change in behaviors leading to tool use in the five infants, and find no increase in any one type of behavior that systematically precedes success. We conclude that sudden success at 18 months probably corresponds to the coming together of a variety of capacities.
• [hal-02326156] Comparison of active and purely visual performance in a multiple-string means-end task in infants

  12 janvier 2024

  The aim of the present study was to understand what factors influence infants’ problem-solving behaviours on the multiple-string task. The main question focused on why infants usually solve the single string-pulling task at 12 months at the latest, whereas most 16-month-old infants still cannot solve the task when several strings are presented, only one of which is attached to the desired object. We investigated whether this difficulty is related to infants’ ability to inhibit their spontaneous immediate actions by comparing active and purely visual performance in this task. During the first part of the experiment, we assessed the ability of infants aged 16–20 months to solve the multiple-string task. The infants were then divided into three groups based on performance (a “failure” group, an “intermediate” group, and a “success” group). The results of this action task suggest that there were differences in infants’ performance according to their level of inhibitory control of their preferred hand. In the second part of the experiment, the three groups’ predictive looking strategies were compared when seeing an adult performing the task. We found that only infants who successfully performed the action task also visually anticipated which string the adult had to pull in the visual task. Our results suggests that inhibitory control was not the only factor influencing infants’ performance on the task. Furthermore, the data support the direct matching hypothesis (Rizzolatti and Fadiga, 2005), according to which infants need to be able to perform actions themselves before being able to anticipate similar actions performed by others.
• [hal-04390049] Pigeons discriminate between human feeders

  12 janvier 2024

  Considered as plague in many cities, pigeons in urban areas live close to human activities and exploit this proximity to find food which is often directly delivered by people. In this study, we explored the capacity of feral pigeons to take advantage of this human-based food resource and discriminate between friendly and hostile people. Our study was conducted in an urban park. Pigeons were fed by two experimenters of approximately the same age and skin colour but wearing coats of different colours. During the training sessions, the two human feeders displayed different attitudes: one of the feeders was neutral and the second was hostile and chased away the pigeons. During the two test phases subsequent to the training phase, both feeders became neutral. Two experiments were conducted, one with one male and one female feeder and the second with two female feeders. In both experiments, the pigeons learned to quickly (six to nine sessions) discriminate between the feeders and maintained this discrimination during the test phases. The pigeons avoided the hostile feeder even when the two feeders exchanged their coats, suggesting that they used stable individual characteristics to differentiate between the experimenter feeders. Thus, pigeons are able to learn quickly from their interactions with human feeders and use this knowledge to maximize the profitability of the urban environment. This study provides the first experimental evidence in feral pigeons for this level of human discrimination.
• [hal-04329099] Studying Female Reproductive Activities in Relation to Male Song

  7 décembre 2023

  [...]
• [hal-04329110] Eavesdropping on Male Singing Interactions Leads to Differential Allocation in Eggs

  7 décembre 2023

  Abstract Females invest differently in their eggs depending on the quality of their mates. In oscines, female investment is influenced by the quality of male song. In domestic canaries Serinus canaria , as well as in black‐capped chickadees Poecile atricapillus , females pay attention not only to the intrinsic quality of male song but can also gather information, by eavesdropping on male–male singing interactions, on the relative quality of males. During these interactions, overlapping the song of the rival is more threatening than alternating. Moreover eavesdropping female canaries have been shown to prefer the overlapping song rather than the overlapped song. The present study was designed to assess the effect of the information gathered by eavesdropping on female investment in eggs. First, we broadcasted overlapping interactions to female canaries. Then, we broadcasted to each female one of the two songs previously heard and collected eggs. Females exposed to overlapping songs laid eggs with greater yolk ratio than females exposed to overlapped songs. In contrast, yolk testosterone quantity and concentration were not affected by the treatment. Moreover, we found a variation between eggs with regard to the testosterone deposited in yolk: both quantity and concentration increased with laying order. Our results suggest that female canaries use information gathered by eavesdropping to differentially allocate resources into the eggs. They suggest that singing interactions could influence chick quality via female investment.
• [hal-04329106] Heaven It's My Wife! Male Canaries Conceal Extra-Pair Courtships but Increase Aggressions When Their Mate Watches

  7 décembre 2023

  [...]
• [hal-04243919] Amitié, intimité émotionnelle et rôles de sexe à l'adolescence

  17 octobre 2023

  La recherche porte sur l'intimité émotionnelle perçue par les adolescents en classes de 4ème ou 3ème dans leurs amitiés dyadiques. Les différences inter-sexes de perception du de l'intimité sont supposées résulter des rôles de sexe plutôt que refléter une supériorité des habiletés sociales des filles. On faisait l'hypothèse que les garçons perçoivent moins d'intimité que les filles dans l'amitié mono-sexuée, mais que garçons et filles ont la même perception de l'intimité dans l'amitié bisexuée. Des adolescents français de 13 à 14 ans ont rempli un questionnaire évaluant la perception de leurs amitiés. Les résultats confirment l'hypothèse. La discussion porte sur le rôle des expériences entre pairs dans ces résultats. Certaines implications pour la supervision éducative des groupes de pairs sont proposées.

ACTUALITES

2023/06/30 - Articles de Johana Ryšavá

• Infants can distinguish between sounds of different bird species, as discovered at the University of Nanterre
• Why should we fight for the education of our children?

2022/04/07 - Michel Kreutzer, sur France Culture (du 04/04/2022 au 07/04/2022 - disponible en podcast en intégralité dès le lundi après la diffusion du premier épisode), dans l'émission LSD -  Série documentaire "L'intelligence du vivant", de Franck Bessière, réalisée par Anne Fleury
1er épisode - "Définir le vivant" « Depuis pas mal d'années, on se rend compte que les êtres vivants, les organismes, notamment les vertébrés supérieurs, les oiseaux, les mammifères, recherchent également ce qui est source de plaisir. Un vivant, c'est donc aussi un être qui recherche des plaisirs et qui essaie d'éviter les déplaisirs. C'est une des raisons sans doute pour laquelle aujourd'hui, on donne tant d'importance à la souffrance animale et qu'on estime que l'on doit se donner des règles éthiques dans nos relations avec les animaux. »
2ème épisode - "L'humain un vivant d'exception"
3ème épisode - "Dans la tête des animaux" « Les émotions entrent pleinement dans les études éthologiques, qui ne se limitent donc plus seulement aux comportements. »
4ème épisode - "Le génie du vivant"

2022/03/30 - Michel Kreutzer, au Musée du Quai Branly - Université populaire 2021/2022, Thème 2 : Le corps - "L'"apprendre animal" : comment le savoir se transmet et s'apprend chez les animaux" 
2021/12/07 - Rana Esseily, Carla Aimé, Dalila Bovet et Maya Gratier, à la Philharmonie de Paris - Colloque "Pédagogie du chant choral" - "Résultats de l'étude scientifique -  impacts sur les capacités psychosociales, les apprentissages scolaires et le bien-être des enfants" (10h20)
https://philharmoniedeparis.fr/fr/activite/colloque/23002-pedagogie-du-chant-choral
2021/10/26 - Michel Kreutzer, sur France Inter, dans l’émission "Grand bien vous fasse" - "Autour des ‘Folies animales'"
2021/10/13 - Michel Kreutzer interviewé par Caroline Lachowski, sur RFI , dans l'émission "Autour de la question" - "La folie est-elle le propre de l’homme ?"
2021/10/11 - Rana Esseily sur France Culture, dans l'émission "La méthode scientifique" - "Rire : c’est du sérieux!"
2021/03/28 - Michel Kreutzer, interviewé par Octave Larmagnac-Matheron, dans Philosophie magazine - "Zoopsychiatrie : À la découverte des folies animales"
2021/03/25 - Michel Kreutzer, invité de l’association CVA (Connaissance et Vie d’Aujourd’hui) de Lille - Conférence "Éthologie : sommes-nous tous des bêtes ?"


ARCHIVES TELE / RADIO
2017/10/26 : France Infos junior - "Que se passe-t-il dans la tête des bébés ?"
2017/03/26 : France Inter - "Les Savanturiers" - en direct du salon du livre (à partir de 40 min 20) pour la promotion de La science à Contrepied paru aux éditions Belin.
2017/04/12 : France 3 - Le monde de Jamy : "Ces animaux si proches de nous"
2015/01/02 : France 5 - C dans l'air : "Mon chat est-il une personne ?"
2014/07/07 : France culture - Les matins d'été, 2ème partie : Les invités culture/Idées. "Malin comme un corbeau", avec deux éthologues Agatha Lievin-Bazin et Valérie Dufour (à partir de la 98ème minute).
2013/06 : NBC News - "Finches sing like birds and their dad taught them how"
2014/04 : France Culture - "L'intelligence du perroquet"
2013/10 : France Culture - Emission Continent Science : "L’homosexualité animale" (audio 54').
Cité des sciences et de l'industrie - Cycle de conférences Universciences "Corps et esprit : indissociables" : "Accéder à la vie subjective des animaux" - Michel Kreutzer.
2012/12 : The Telegraph "Parrot listens to Scissor Sisters' music".
2012/12 : France 5 - Emission "On n'est pas que des cobayes" : "Les éléphants ont-ils peur des souris".
2011/05 : France Inter - Emission "Vivre avec les bêtes", 29 mai :  http://www.franceinter.fr/em/vivre-avec-les-betes/105163 (05/2011)

ARCHIVES PRESSE ECRITE
2019/11/30 : The Economist - Male nightingales spend the winter practising.
2019/11/26 : New Scientist - Nightingales practise new songs in winter to impress mates in spring.
2017/03 :  Sciences Psy - Le tempo de notre quotidien - Et si nous prenions le temps ?, pp.30.
2014/12 : Santé magazine, n°469 sur l'empathie.
2014/09/03 : BMC - The unheard message of larksong.
2014/06 : JDD - L'intelligence des corbeaux
2013/11 : JDD - Comment les oiseaux apprennent-ils à chanter ?
2012/03&04 : Cerveau&Psycho - Le perroquet mentaliste.
2011 : Le Pigeon en Ville - La vie sociale du pigeon Bizet.
2011/12 : Le Républicain Lorrain - Les pigeons sont physionomistes.
2011/08 : Futura Sciences -  Les canaris font leur show... et s'adaptent à leur public !
2011/08 : Les Echos - Le perroquet, une langue et un cerveau.
2011/05 : BBC News - Parrots choose to work together.
2011/05 : Maxisciences - Intelligence du perroquet gris : collaboration et personnalité.
2011/05 : PhysOrg - Parrots display teamwork and decision-making skills.
2009/04 : Science Actualité, Universciences - Des piafs malins comme des singes.
2005/02 : BBC News - Sleep helps birds sing better.
A good night's sleep helps young birds master the art of singing, but only after a rather groggy start, Nature magazine has reported.
Savoirs Essonne - Masculin/féminin : le genre existe-t-il chez les animaux ?

Contribution de Laurent Nagle : "Les lions et les lionnes : des prédateurs aux moeurs parfois surprenantes" et  "L'antiquité gréco-romaine : un foyer d'anti-spécistes avant l'heure ?"
Le lion dans le pourtour méditerranéen sous la direction de Margaux Spruyt et Véronique Vassal - journées d'études du 11 & 12 mai 2023 à l'Institut Catholique de Paris. Editions du Cerf, janvier 2025