A longitudinal comparison of maternal behaviour in German urban humans (Homo sapiens) and captive chimpanzees (Pan troglodytes)

Comparative perspectives are crucial in the study of human development, yet longitudinal comparisons of humans and other primates are still relatively uncommon. Here, we combined theoretical frameworks from cross-cultural and comparative psychology, to study maternal style in 10 mother-infant pairs of German urban humans (Homo sapiens) and 10 mother-infant pairs of captive chimpanzees (Pan troglodytes), during the first year of infants' development. We conducted focal observations of different behaviours (i.e. nursing, carrying, body contact, touching, grooming, restraining, approaching, leaving, rejection, aggression, mutual gaze, object stimulation), during natural interactions. Analyses revealed a more distal maternal style in WEIRD humans than in captive chimpanzees, with different behaviours being generally more common in one of the two species throughout development. For other behaviours (i.e. nursing), developmental trajectories differed between WEIRD humans and captive chimpanzees, although differences generally decreased through infants' development. Overall, our study confirms functional approaches as a valid tool for comparative longitudinal studies.

Understanding others' preferences: A comparison across primate species and human societies

We investigated children's and non-human great apes' ability to anticipate others' choices from their evident food preferences-regardless of whether these preferences deviate or align with one's own. We assessed children from three culturally-diverse societies (Namibia, Germany, and Samoa; N = 71; age range = 5-11) and four non-human great ape species (chimpanzees (Pan troglodytes), bonobos (Pan paniscus), gorillas (Gorilla gorilla), and orangutans (Pongo abelii); N = 25; age range = 7-29) regarding their choices in a dyadic food-retrieval task. Across conditions, participants' preferences were either aligned (same preference condition) or opposed (opposite preference condition) to those of their competitors. Children across societies altered their choices based on their competitor's preferences, indicating a cross-culturally recurrent capacity to anticipate others' choices relying on preferences-based inferences. In contrast to human children, all non-human great apes chose according to their own preferences but independent of those of their competitors. In sum, these results suggest that the tendency to anticipate others' choices based on their food preferences is cross-culturally robust and, among the great apes, most likely specific to humans.

Face to face interactions in chimpanzee (Pan troglodytes) and human (Homo sapiens) mother-infant dyads

Human mothers interact with their infants in different ways. In Western, educated, industrialized, rich and democratic (WEIRD) societies, face-to-face interactions and mutual gazes are especially frequent, yet little is known about their developmental trajectories and if they differ from those of other primates. Using a cross-species developmental approach, we compared mother-infant interactions in 10 dyads of urban humans from a WEIRD society (Homo sapiens) and 10 dyads of captive zoo-based chimpanzees (Pan troglodytes), when infants were one, six and 12 months old. Results showed that face-to-face interactions with mutual gaze events were common in both groups throughout the infant's first year of life. The developmental trajectories of maternal and infants' looks partially differed between species, but mutual gaze events were overall longer in humans than in chimpanzees. Mutual gazes were also more frequent in humans, peaking at six months in humans, while increasing with age in chimpanzees. The duration and frequency of mutual gazes varied across contexts in both groups, with mutual gazes being longer during caring/grooming and feeding contexts. These findings confirm that some aspects of early socio-cognitive development are shared by humans and other primates, and highlight the importance of combining developmental and cross-species approaches to better understand the evolutionary roots of parenting behaviour. This article is part of a discussion meeting issue 'Face2face: advancing the science of social interaction'.

Servant leadership and employee wellbeing: A crosscultural investigation of the moderated path model in Canada, Pakistan, China, the US, and Brazil

Drawing on samples from Canada, Pakistan, China, the US, and Brazil comprising over 800 employees, we examined whether servant leaders (SL) - characterized as putting the needs of others above their own - promote employees’ well-being via autonomous motivation, accounting for employees’ power distance and collectivism values as moderating variables. Autonomous motivation, a type of self-regulation, sustains one’s well-being. Personal values facilitate one’s work behaviors cross-culturally. Multigroup confirmatory factor analysis (CFA) results confirmed matrix invariance of all the measures. The path and moderation analyses result using multilevel structural equation modeling (SEM) supported the positive direct and indirect paths among SL, autonomous motivation, and psychological well-being across the five cultures; Collectivistic value negatively moderated the relationship between servant leadership and autonomous motivation across the Chinese and US samples. In addition, with only a limited number of items, measurements of SL and vitality achieved scalar invariance. ANOVA test results also confirmed the significant comparative differences in these two variables among the cultural groups. Findings in this research provided robust and empirical support for the motivational effects of the servant leadership theory across the globe. Theoretical and practical implications for evidence-based cross-cultural management practices and future directions for leadership training in diverse cultural contexts are discussed.

A predictive processing framework of tool use

In this paper I introduce the theory of predictive processing as a unifying conceptual framework to account for the human ability to use and innovate tools. I explain the basic concepts of predictive processing and illustrate how this framework accounts for the development of tool use in young infants and for findings in the neuropsychological and neuroscientific literature. Then, I argue that the predictive processing model needs to be complemented with a functional-evolutionary perspective, according to which the developmental and neurocognitive mechanisms should be understood in relation to the adaptive function that tools subserve. I discuss cross-cultural and comparative studies on tool use to illustrate how tools could facilitate a process of cumulative cultural and technological evolution. Furthermore, I illustrate how central premises of the predictive processing framework, such as the notion of Bayesian inference as a general principle and the role of prediction-error-updating, speak to central debates in evolutionary psychology, such as the massive modularity hypothesis and the trade-off between exploitation and innovation. Throughout the paper I make several concrete suggestions for future studies that could be used to put the predictive processing model of tool use to the test.

Priming third-party ostracism does not lead to increased affiliation in three Serbian communities

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 (over)imitation following primes depicting social exclusion. However, all prior studies to date tested this effect in children from strongly socially independent societies, emphasizing individual freedom and psychological autonomy. The current study tested whether these effects also occur among children growing up in a society where social interdependence is emphasized more strongly. We assessed affiliative reactions to video primes depicting either third-party ostracism or control stimuli among 128 preschoolers (M_age = 4.73 years) from an urban community (Belgrade), a semi-urban community (Pozarevac), and a rural community (Kostolac) in Serbia. Across communities, children detected ostracism when it was depicted in the priming stimuli. However, children neither drew more affiliative pictures nor engaged in more faithful overimitation following primes depicting ostracism as compared with control stimuli. The two measures for affiliation (i.e., affiliative drawings and increased overimitation) were not linked on an individual level. Although these results suggest that young children from diverse societies are capable of recognizing third-party social exclusion, their response to such information is strongly shaped by cultural values on social interdependence.

A cross-cultural investigation of young children's spontaneous invention of tool use behaviours

Through the mechanisms of observation, imitation and teaching, young children readily pick up the tool using behaviours of their culture. However, little is known about the baseline abilities of children's tool use: what they might be capable of inventing on their own in the absence of socially provided information. It has been shown that children can spontaneously invent 11 of 12 candidate tool using behaviours observed within the foraging behaviours of wild non-human apes (Reindl et al. 2016 Proc. R. Soc. B 283, 20152402. (doi:10.1098/rspb.2015.2402)). However, no investigations to date have examined how tool use invention in children might vary across cultural contexts. The current study investigated the levels of spontaneous tool use invention in 2- to 5-year-old children from San Bushmen communities in South Africa and children in a large city in Australia on the same 12 candidate problem-solving tasks. Children in both cultural contexts correctly invented all 12 candidate tool using behaviours, suggesting that these behaviours are within the general cognitive and physical capacities of human children and can be produced in the absence of direct social learning mechanisms such as teaching or observation. Children in both cultures were more likely to invent those tool behaviours more frequently observed in great ape populations than those less frequently observed, suggesting there is similarity in the level of difficulty of invention across these behaviours for all great ape species. However, children in the Australian sample invented tool behaviours and succeeded on the tasks more often than did the Bushmen children, highlighting that aspects of a child's social or cultural environment may influence the rates of their tool use invention on such task sets, even when direct social information is absent.

Addressing Methodological Challenges in Culture-Comparative Research

We address methodological challenges in cross-cultural and cultural psychology. First, we describe weaknesses in (quasi-)experimental designs, noting that cross-cultural designs typically do not allow any conclusive evidence of causality. Second, we argue that loose adherence to methodological principles of psychology and a focus on differences, while neglecting similarities, is distorting the literature. We highlight the importance of effect sizes and discuss the role of Bayesian statistics and meta-analysis for cross-cultural research. Third, we highlight issues of measurement bias and lack of equivalence, but note that recent large-scale projects involving researchers across many countries from the beginning of a study have much potential for overcoming biases and improving standards of equivalence. Fourth, we address some implications of multilevel models. Cultural processes are multilevel by definition and recent statistical advances can be used to explore these issues further. We believe this is an area where much theoretical work needs to be done and more rigorous methods applied. Fifth, we argue that the definition of culture and the psychological organization of cross-cultural differences as well as the definition of cultural populations to which research findings are generalized requires more attention. Sixth, we address the scope for anchoring cross-cultural research in biological variables and by asking multiple questions simultaneously, as advocated by Tinbergen for classical ethology. Bringing these discussions together, we provide recommendations for enhancing the methodological strength of culture-comparative studies to advance cross-cultural psychology as a scientific discipline.