Daniel Haun

University of Leipzig · Early Child Development and Culture

Interactions with peers are fundamental to socio-cognitive development, but assessing peer interactions in standardized experiments is challenging. Therefore, researchers commonly utilize puppetry to simulate peers. This Registered Report investigated urban German children's (AgeRange = 3.5-4.5 years; N = 144; 76♀) mind ascriptions and social cogni...

Partner choice promotes competition among individuals to be selected as a cooperative partner, a phenomenon referred to as competitive altruism. Our study explores chimpanzees' competitive altruism in a triadic Ultimatum Game where two proposers can send offers to a responder who can only accept one offer. Chimpanzees engaged in competitive altruis...

Young children share equally when they acquire resources through collaboration with a partner, yet it is unclear whether they do so because in such contexts resources are encountered as common and distributed in front of the recipient or because collaboration promotes a sense of work-based fairness. In the current studies, 5- and 8-year-old childre...

Negative early experiences can have detrimental effects on social functioning in later life, both in humans as well as in other socially-living animals. In zoo-housed chimpanzees, recent evidence suggests that there may be a lingering signature of early trauma on individuals’ social interaction tendencies as measured by social proximity and groomin...

Compared to other species, the extent of human cooperation is unparalleled. Such cooperation is coordinated between community members via social norms. Developmental research has demonstrated that very young children are sensitive to social norms, and that social norms are internalized by middle childhood. Most research on social norm acquisition h...

Short-term memory is implicated in a range of cognitive abilities and is critical for understanding primate cognitive evolution. To investigate the effects of phylogeny, ecology and sociality on short-term memory, we tested the largest and most diverse primate sample to date (421 non-human primates across 41 species) in an experimental delayed-resp...

Human relationships are structured in a set of layers, ordered from higher (intimate relationships) to lower (acquaintances) emotional and cognitive intensity. This structure arises from the limits of our cognitive capacity and the different amounts of resources required by different relationships. However, it is unknown whether nonhuman primate sp...

Traditional measures of social cognition used in developmental research often lack satisfactory psychometric properties and are not designed to capture variation between individuals. Here we present TANGO (Task for Assessing iNdividual differences in Gaze understanding - Open); a brief (approx. 5–10min), reliable, open-source task to quantify indiv...

Humans have a deeply rooted sense of fairness, but its emotional foundation in early ontogeny remains poorly understood. Here, we asked if and when 4- to 10-year-old children show negative social emotions, such as shame or guilt, in response to advantageous unfairness expressed through a lowered body posture (measured using a Kinect depth sensor im...

Individual differences in early language abilities are an important predictor of later life outcomes. High-quality, easy-access measures of language abilities are rare, especially in the preschool years. The present study describes the construction of a new receptive vocabulary task for children between 3 and 8 years of age. The task was implemente...

The understanding of developing social brain functions during infancy relies on research that has focused on studying how infants engage in first-person social interactions or view individual agents and their actions. Behavioral research suggests that observing and learning from third-party social interactions plays a foundational role in early soc...

Theories in psychology, cognitive science, anthropology and evolutionary biology use great ape cognition as a reference point to specify the evolutionary dynamics that give rise to complex cognitive abilities and to define the nature of human cognition. This approach requires a comprehensive way of describing great ape cognition to compare it to ot...

Researchers commonly use puppets in development science. Amongst other things, puppets are employed to reduce social hierarchies between child participants and adult experimenters akin to peer interactions. However, it remains controversial whether children treat puppets like real-world social partners in these settings. This study investigated chi...

Human relationships are structured in a set of layers, ordered from higher (intimate relationships) to lower (acquaintances) emotional and cognitive intensity. This structure arises from the limits of our cognitive capacity and the different amounts of resources required by different relationships. However, it is unknown whether nonhuman primate sp...

This study investigates how culture and priming 3- to 7-year-old children ( N = 186) with third-party social exclusion affects their subsequent inclusion of out-group members. Children in societies that tend to value social independence (Germany, New Zealand) and interdependence (Northern Cyprus) were randomly assigned to minimal groups. Next, they...

While most animals play, only humans play games. As animal play serves to teach offspring important life-skills in a safe scenario, human games might, in similar ways, teach important culturally relevant skills. Humans in all cultures play games; however, it is not clear whether variation in the characteristics of games across cultural groups is re...

Tool innovation has played a crucial role in human adaptation. Yet, this capacity seems to arise late in development. Before 8 years of age, many children struggle to solve the hook task, a common measure of tool innovation that requires modification of a straight pipe cleaner into a hook to extract a prize. Whether these findings are generalizable...

When do hurt feelings develop? The emotion of feeling hurt is vital for close relationships because it signals that one has been devalued illegitimately, potentially eliciting guilt and the motivation to repair in the partner. We approached the question of when hurt feelings develop by studying the emergence of sulking behavior as an indicator of h...

Previous research has shown significant effects of race and accent on children’s developing social preferences. Accounts of the primacy of accent biases in the evolution and ontogeny of discriminant cooperation have been proposed, but lack systematic cross-cultural investigation. We report three controlled studies conducted with 5−10 year old child...

Children’s sulking behavior is a salient yet understudied emotional phenomenon. It has been hypothesized to result from hurt feelings, humiliation, and anger, and might thus function as a nonverbal measure in the behavioral studies of these emotions. We conducted three studies that served to develop a comprehensive coding system for children’s sulk...

In the past four decades, the term social tolerance has been utilized to describe, explain, and predict many different aspects of primates' sociality and has been measured with a large range of traits and behaviors. To date, however, there has been little discussion on whether these different phenomena all reflect one and the same construct. This p...

In direct interactions with others, 9-month-old infants’ learning about objects is facilitated when the interaction partner addresses them through eye contact before looking toward an object. In this study we investigated whether similar factors promote infants’ observational learning from third-party interactions. In Experiment 1, 9-month-old typi...

This study examined 7-to-13.5-month-old middle-class Western infants' visual orienting to third-party interactions in parallel with their social attention behavior during own social interactions (Leipzig, Germany). In Experiment 1, 9.5-to-11-month-olds (n = 20) looked longer than 7-to-8.5-month-olds (n = 20) at videos showing two adults interacting...

Past research suggests that children favour their in-group members over out-group members as indicated by selective prosociality such as sharing or social inclusion. This preregistered study examined how playing a cooperative, competitive or solitary game influences German 4- to 6-year-olds’ in-group bias and their general willingness to act prosoc...

Humans in most cultures around the world play rule-based games, yet research on the content and structure of these games is limited. Previous studies investigating rule-based games across cultures have either focused on a small handful of cultures, thus limiting the generalizability of findings, or used cross-cultural databases from which the raw d...

Primate cognition research allows us to reconstruct the evolution of human cognition. However, temporal and contextual factors that induce variation in cognitive studies with great apes are poorly understood. Here we report on a longitudinal study where we repeatedly tested a comparatively large sample of great apes (N = 40) with the same set of co...

Social tolerance is generally treated as a stable, species-specific characteristic. Recent research, however, has questioned this position and emphasized the importance of intraspecific variation. We investigate the temporal stability of social tolerance in four groups of sanctuary-housed chimpanzees over eight years using a commonly employed measu...

Infants are attentive to third‐party interactions, but the underlying mechanisms of this preference remain understudied. This study examined whether 13‐month‐old infants (N = 32) selectively learn cue–target associations guiding them to videos depicting a social interaction scene. In a visual learning task, two geometrical shapes were repeatedly pa...

Chimpanzees act cooperatively in the wild, but whether they afford benefits to others, and whether their tendency to act prosocially varies across communities, is unclear. Here, we show that chimpanzees from neighboring communities provide valuable resources to group members at personal cost, and that the magnitude of their prosocial behavior is gr...

When do hurt feelings develop? In this paper, we want to set the stage for empirical investigations that can answer this neglected question. Thus, we present an integrative theory of hurt feelings according to which hurt feelings in their narrow sense consist of (a) a primary appraisal of an illegitimate devaluation, (b) a secondary appraisal of lo...

Children seek and like to engage in collaborative activities with their peers. This social motivation is hypothesized to facilitate their emerging social-cognitive skills and vice versa. Current evidence on the ontogeny of social motivation and its’ links to social cognition, however, is subject to a sampling bias toward participants from urban Wes...

Young children rely on establishing and maintaining social relationships. As a consequence, social exclusion poses a significant threat that should be avoided actively. Previous research reports that children react to ostracism with an increased tendency to affiliate. For example, they draw more affiliative pictures and engage in more faithful (ove...

Humans have a deeply-rooted sense of fairness, but its emotional foundation in early ontogeny remains poorly understood. Here, we ask if and when children show negative social emotions, such as shame or guilt, in response to advantageous unfairness expressed through a lowered body posture (measured using a Kinect depth sensor imaging camera). We wi...

Vocalizations linked to emotional states are partly conserved among phylogenetically related species. This continuity may allow humans to accurately infer affective information from vocalizations produced by chimpanzees. In two pre-registered experiments, we examine human listeners' ability to infer behavioural contexts (e.g. discovering food) and...

When do hurt feelings develop in childhood? In this paper, we want to set the stage for empirical investigations that can answer this neglected question.

During their preschool years, children from urban, Western populations increasingly use deception and mistrust to regulate social interactions with others who have opposing interests. The ontogeny of these behaviors in rural, non-Western populations remains understudied. This study assessed deception and mistrust within peer interactions among 4- t...

Inferring the evolutionary history of cognitive abilities requires large and diverse samples. However, such samples are often beyond the reach of individual researchers or institutions, and studies are often limited to small numbers of species. Consequently, methodological and site-specific-differences across studies can limit comparisons between s...

Are emotional expressions shaped by innate mechanisms that guide learning, or do they develop exclusively from learning without any innate preparedness? Here we test whether nonverbal affective vocalisations produced by bilaterally congenitally deaf adults contain emotional information that is recognisable to naive listeners. As these deaf individu...

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Understanding intraspecific variation in sociality is essential for characterizing the flexibility and evolution of social systems, yet its study in nonhuman animals is rare. Here, we investigated whether chimpanzees exhibit population-level differences in sociality that cannot be easily explained by differences in genetics or ecology. We compared...

For over a century, theories of human intelligence have concentrated on a single general factor, the psychometric g, which is used to estimate reasoning ability and cognitive flexibility, i.e. general intelligence. To better understand the evolution of general intelligence, it is important to identify the presence of a psychometric g in nonhuman an...

Although there is good evidence that social animals show elaborate cognitive skills to deal with others, there are few reports of animals physically using social agents and their respective responses as means to an end—social tool use. In this case study, we investigated spontaneous and repeated social tool use behavior in chimpanzees (Pan troglody...

In the Smaldino et al. study ‘Sigmoidal Acquisition Curves are Good Indicators of Conformist Transmission’, our original findings regarding the conditional validity of using population-level sigmoidal acquisition curves as means to evidence individual-level conformity are contested. We acknowledge the identification of useful nuances, yet conclude...

Comparative cognition is a field of enquiry that aims to research cognition by comparing its characteristics across animal species. Cross‐species comparisons can separate cognitive skills that are widely shared across species from those that are rare or even unique to any particular species. Comparisons across species can also help researchers to u...

Conformity refers to individuals adjusting their opinion and/or behavior to match the majority of group members. As a psychological phenomenon, conformity has been studied in the context of social influence theories, where it is typically equated with persuasion by a majority of confederates expressing an erroneous opinion. In terms of adaptive lea...

Social information use is a pivotal characteristic of the human species. Avoiding the cost of individual exploration, social learning confers substantial fitness benefits under a wide variety of environmental conditions, especially when the process is governed by biases toward relative superiority (e.g., experts, the majority). Here, we examine the...

Psychology must confront the bias in its broad literature towards the study of participants developing in environments unrepresentative of the vast majority of the world’s population. Here, we focus on the implications of addressing this challenge, highlight the need to address over-reliance on a narrow participant pool, and emphasize the value and...

The ‘grooming handclasp’ is one of the most well-established cultural traditions in chimpanzees. A recent study by Wrangham et al. [1] reduced the cultural scope of grooming-handclasp behavior by showing that grooming-handclasp style convergence is “explained by matrilineal relationship rather than conformity” [1] . Given that we previously reporte...

In the present research, we investigate the communicative strategies of 20 month old human infants and great apes when requesting rewards from a human experimenter. Infants and apes both adapted their signals to the attentional state of the experimenter as well as to the location of the reward. Yet, while infants frequently positioned themselves in...

GLMM analysis of number of switches to the experimenter’s side. (DOCX)

GLMM analysis of number of switches to the other side. (DOCX)

GLMM analysis of the number of auditory signals produced at the other side. (DOCX)

GLMM analysis of the number of visual gestures produced at the other side. (DOCX)

TS condition. Towards-same condition; experimenter on the right side; reward on the right side. (MP4)

GLMM analysis of the number of auditory signals produced at the experimenter’s side. (DOCX)

GLMM analysis of the number of pointing gestures directed to the experimenter’s side. (DOCX)

AD condition. Away-different condition; experimenter on the right side; reward on the left side. (MP4)

Raw data and summarized data for duration of stay, number of switches, auditory signals, visual and pointing gestures. (XLSX)

GLMM analysis of the number of visual gestures produced at the experimenter’s side. (DOCX)

TD condition. Towards-different condition; experimenter on the left side; reward on the right side. (MP4)

AS condition. Away-same condition; experimenter on the left side; reward on the left side. (MP4)

For the first time, chimpanzees have been observed using tools to clean the corpse of a deceased group member. A female chimpanzee sat down at the dead body of a young male, selected a firm stem of grass, and started to intently remove debris from his teeth. This report contributes novel behaviour to the chimpanzee’s ethogram, and highlights how cr...

Non-human animals sometimes show marked intraspecific variation in their cognitive abilities that may reflect variation in external inputs and experience during the developmental period. We examined variation in exploration and cognitive performance on a problem-solving task in a large sample of captive orang-utans (Pongo abelii & P. pygmaeus, N =...

Conformist transmission, defined as a disproportionate likelihood to copy the majority, is considered a potent mechanism underlying the emergence and stabilization of cultural diversity. However, ambiguity within and across disciplines remains as to how to identify conformist transmission empirically. In most studies, a population level outcome has...

Figure 1. A population of N = 100 individuals is randomly initialized with one of two behaviours. At each time step, a model and an observer are randomly extracted from the population, and the observer always copies the model. The simulation ends at 10 000 time steps, i.e. 10 000 possible interactions. Results are based on 1000 replications of the...

Relational reasoning is a hallmark of sophisticated cognition in humans [1, 2]. Does it exist in other primates? Despite some affirmative answers [3-11], there appears to be a wide gap in relational ability between humans and other primates-even other apes [1, 2]. Here, we test one possible explanation for this gap, motivated by developmental resea...