Katie Elizabeth Slocombe

Learning to regulate one's emotions is a key feature of socio‐emotional development. The still‐face experiment—which measures how infants respond to a sudden change in maternal responsiveness—has long been considered a reliable indicator of infant reactivity and regulation. However, as a paradigm established to fit Western, middle‐class industrialized contexts, its robustness in other cultural contexts, has been questioned. Differences in responses to the still‐face experiment are likely shaped by variation in infant‐caregiver interactions and practices. To expand the literature and address sampling biases, we conducted the still‐face experiment with 10‐month‐old infants ( N = 138, 68 female) across three sites, in rural and urban Uganda and urban UK. Across sites, we found the expected patterns of decreased infant positive affect and gaze toward their caregiver in the still‐face phase. However, while infants in urban Uganda and the UK exhibited increased negative affect when their mother ceased interacting, infants from rural Uganda did not. Our findings highlight important variation across socio‐cultural contexts in infant emotional reactivity and interaction style, suggesting that infants' responses to the still‐face paradigm may be shaped by the broader caregiving environments in which they develop.

Prosocial behavior, including instrumental helping, emerges early in development, but the role parental attitudes and practices take in shaping the emergence of early helping across different cultural contexts is not well understood. We took a longitudinal approach to investigate maternal socialization of early helping across two different cultural groups. Participants were mother-infant dyads from urban/suburban York, United Kingdom (43 infants: 21 females, 22 males) and the rural Masindi District, Uganda (39 infants: 22 females, 17 males). We examined cultural variations in mother's helping-related parenting practices toward 14- and 18-month-olds and infants' actual helping in experimental tasks at 18 months. We then asked whether maternal parenting practices and socialization goals predicted individual variation in infant helping. We found that U.K. mothers scaffolded infant helping using a larger range of strategies than Ugandan mothers, but expecting an infant to help was more common in Uganda than in the United Kingdom. Moreover, we found that the Ugandan infants were more likely and often quicker to help an adult in need than the U.K. infants. Finally, we found that maternal scaffolding behaviors positively predicted individual variation in infant helping at 18 months in the United Kingdom, but not in Uganda. By contrast, maternal alignment with relational socialization goals at 11 months positively predicted infant helping at 18 months in the Ugandan, but not in the U.K., sample. These results indicate that early instrumental helping behavior varies across societies and that maternal socialization goals and scaffolding behaviors can shape infant helping in culturally specific ways. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Theoretical accounts assume that key features of human social cognition are universal. Here we focus on gaze-following, the bedrock of social interactions and coordinated activities, to test this claim. In this comprehensive cross-cultural study spanning five continents and 17 distinct cultural communities, we examined the development of gaze-following in early childhood. We identified key processing signatures through a computational model that assumes that participants follow an individual’s gaze by estimating a vector emanating from the eye-center through the pupil. Using a single reliable touchscreen-based task, we found these signatures in all communities, suggesting that children worldwide processed gaze in highly similar ways. Absolute differences in performance between groups are accounted for by a cross-culturally consistent relationship between children’s exposure to touchscreens and their performance in the task. These results provide strong evidence for a universal process underlying a foundational socio-cognitive ability in humans that can be reliably inferred even in the presence of cultural variation in overt behavior.

Non-human vocalizations carrying information regarding external events have been likened to referential words and are thus integral for exploring the origins of linguistic reference. Previous research suggests receivers decode this referential information and some studies have indicated that such calls can, like in humans, evoke mental representations of the referent in receivers. However, the nature of these representations remains ambiguous. Specifically, whether calls elicit affect-based representations (e.g. signaller fear after alarm calls) or object-based representations (e.g. threats encountered by signallers after alarm calls), or both, in listeners remains untested. To investigate this, we conducted a match-to-sample task with a language-competent bonobo (Kanzi) asking him to match playbacks of conspecific alarm and food-associated calls to lexigrams representing either affect-based (‘scare’, ‘surprise’) or object-based (‘snake’, ‘food’) content. Kanzi matched alarm calls to ‘scare’ and ‘snake’ lexigrams at above chance levels regardless of caller familiarity but did not match food-associated calls to either ‘surprise’ or ‘food’ targets. We propose environmental cues are required to interpret food-associated calls that occur across a variety of contexts. These findings suggest bonobo alarm calls evoke object- and affect-based representations for Kanzi, indicating the mechanisms underlying the perception of non-human vocalizations may be more similar to those in language than previously thought.

Recent research has produced evidence for basic combinatorial abilities in the vocal systems of different animal species. Here, we investigate the structure of gesture sequences in Eastern chimpanzees ( Pan troglodytes schweinfurthii ) to detect whether gestural communication shows non-random combinations and how combinatorial rules influence predictability. Gesture, as compared to vocalization, offers greater flexibility in how signals are combined—for example overlapping in time — and as the parsing of signals into sequences is dependent on researcher decisions, we employ a multiverse approach, considering four different definitions of what constitutes a ‘sequence’ based on varying time thresholds. Our results indicate that sequences tend to be short (even with the most liberal time-window) and that transitions between some gesture types occur more frequently than expected by chance, with some transitions showing significant association across all time-windows. These transitions often involve repetition, suggesting persistence as a key aspect of chimpanzee gestural sequences. Information about previous gestures reduced uncertainty in predicting subsequent gestures. The order of gestures within sequences appears to be less critical than their cooccurrence, challenging assumptions based on the linear patterning derived from vocal communication. Our findings highlight the importance of methodological choices in sequence definition and suggest that chimpanzee gestural communication is characterised by a mix of predictability and flexibility, with implications for understanding the evolution of complex communication systems.

Adoption is an unusual behaviour across taxa, and for adoption to be successful, with the infant surviving to independence, the adoptive parent must be able to provide appropriate nutrition and care. Successful adoption has now been reported in several nonhuman primate species and here we add a case in wild yaki (Sulawesi crested macaque, Macaca nigra ). We observed the adoption of an approx. 2-week-old infant by a female with her own approx. 3-week-old infant who went on to carry, nurse, and care for both infants until they both became independent. The adoptive and biological mother had each previously raised the same number of offspring (5). There was no evidence of aggressive transfer and we did not observe any attempts by the adopted infant’s biological mother to retrieve her. The biological mother went on to have another infant 8 months later while the adoptive mother was still caring for her other infant. This case may reflect some of the health costs and reproductive benefits of adoption for nonhuman primates.

One promising method to tackle the question, “In which modality did language evolve?” is by studying the ontogenetic trajectory of signals in human’s closest living relatives, including chimpanzees (Pan troglodytes). Concerning gestures, current debates centre on four different hypotheses: “phylogenetic ritualization”, “social transmission through imitation”, “ontogenetic ritualization”, and “social negotiation”. These differ in their predictions regarding idiosyncratic gestures, making such occurrences a crucial area of investigation. Here, we describe a novel and potential idiosyncratic behaviour — ‘hand-on-eye’ — which was initially observed in one mother-infant dyad in a community of chimpanzees living in the wild. We systematically investigated the form, sequential organisation, intentionality, usage, function, and distribution of the behaviour over a five-year period. The results showed that ‘hand-on-eye’ was nearly exclusively deployed in a single mother-infant dyad, was accompanied by hallmarks of intentionality, and served to initiate or resume joint dorsal travel. Although the behaviour was observed once in each of three other mother-infant dyads, these lacked the same frequency and hallmarks of intentionality. ‘Hand-on-eye’ thus qualifies as an idiosyncratic gesture. The proposed developmental pathway gives support to both the “ontogenetic ritualization” and “social negotiation” hypotheses. It also stresses the crucial need for longitudinal approaches to tackle developmental processes that are triggered by unique circumstances and unfold over relatively long time windows.

Cross-cultural studies are crucial for investigating the cultural variability and universality of cognitive developmental processes. However, cross-cultural assessment tools in cognition across languages and communities are limited. This paper describes a gaze following task designed to measure basic social cognition across individuals, ages, and communities (TANGO–CC). The task was developed and psychometrically assessed in one cultural setting and, with input of local collaborators, adapted for cross-cultural data collection. Minimal language demands and the web-app implementation allow fast and easy contextual adaptations to each community. The TANGO–CC captures individual- and community-level variation and shows good internal consistency in a data set from 2.5- to 11-year-old children from 17 diverse communities. Within-community variation outweighed between-community variation. We provide an open-source website for researchers to customize and use the task (https://ccp-odc.eva.mpg.de/tango-cc). The TANGO–CC can be used to assess basic social cognition in diverse communities and provides a roadmap for researching community-level and individual-level differences across cultures.

Parsing signals from noise is a general problem for signallers and recipients, as well as for researchers studying communicative systems. Substantial research efforts have been invested in comparing how other species encode information and meaning in their signals, and how signalling is structured. However, our ability to do so depends on identifying and discriminating signals that represent meaningful units of analysis. Early approaches to defining signal repertoires applied top- down approaches, classifying cases into predefined signal types. Recently, more labour-intensive methods have taken a bottom-up approach describing the features of each signal in detail and clustering cases into types based on patterns of similarity between them in multi-dimensional feature-space that were previously undetectable. Nevertheless, it remains essential to assess whether the resulting repertoires are composed of relevant units from the perspective of the species using them, and redefining repertoires when additional data makes more detailed analyses feasible. In this paper we provide a framework that takes data from the largest set of wild chimpanzee ( Pan troglodytes ) gestures currently available, splitting gesture types at a fine scale based on modifying features of gesture expression and then determining whether this splitting process increases the information content of the communication system. Our method allows different features of interest to be incorporated into the splitting process, providing substantial future flexibility across - for example - species, populations, and levels of signal granularity. In doing so we provide a powerful tool allowing researchers interested in gestural communication to establish repertoires of relevant units for subsequent analyses within and between systems of communication.

Early life environments afford infants a variety of learning opportunities, and caregivers play a fundamental role in shaping infant early life experience. Variation in maternal attitudes and parenting practices is likely to be greater between than within cultures. However, there is limited cross-cultural work characterising how early life environment differs across populations. We examined the early life environment of infants from two cultural contexts where attitudes towards parenting and infant development were expected to differ: in a group of 53 mother-infant dyads in the UK and 44 mother-infant dyads in Uganda. Participants were studied longitudinally from when infants were 3– to 15–months-old. Questionnaire data revealed the Ugandan mothers had more relational attitudes towards parenting than the mothers from the UK, who had more autonomous parenting attitudes. Using questionnaires and observational methods, we examined whether infant development and experience aligned with maternal attitudes. We found the Ugandan infants experienced a more relational upbringing than the UK infants, with Ugandan infants receiving more distributed caregiving, more body contact with their mothers, and more proximity to mothers at night. Ugandan infants also showed earlier physical development compared to UK infants. Contrary to our expectations, however, Ugandan infants were not in closer proximity to their mothers during the day, did not have more people in proximity or more partners for social interaction compared to UK infants. In addition, when we examined attitudes towards specific behaviours, mothers’ attitudes rarely predicted infant experience in related contexts. Taken together our findings highlight the importance of measuring behaviour, rather than extrapolating expected behaviour based on attitudes alone. We found infants’ early life environment varies cross-culturally in many important ways and future research should investigate the consequences of these differences for later development.