?
Leaders-Cheaters in Male Group Cooperation: Differences in Nonverbal Communication and Genetic Factors
Here we report on the results of an exper- imental study investigating “who?” emerges as a leader in the context of male group cooperation and “how?” they do that. The study was designed based on the iterated Public Goods Game, played face-to-face in groups composed of four male strangers. The game involved inter- actions both with and without communi- cation to allow the assessment of individ- ual cooperative strategies, leadership potential, and individual features of posi- tive nonverbal expressiveness during interactions. Along with the individual behavioural characteristics we have addressed personality traits (the Big Five) and an oxytocin receptor gene polymorphism (OXTR: SNP rs53576; A/G) as putative markers of individual sociability. Our results revealed that emergent leaders most often employed the strategy of unconditional coopera- tion (“altruism”) and were characterized by enhanced positive facial expressive- ness and extraversion compared to non- leaders. However, a fraction of emergent leaders (25%) turned out to be occasion- al free-riders (“cheaters”). Their distinc- tive features were the highest scores on extraversion, exaggerated activity in negotiations, and over-expression of pos- itive nonverbal elements. Given the high efficiency of leaders-cheaters’ behaviour, we consider this result as the evidence for supernormal stimuli functioning in humans. Moreover, leaders-cheaters were characterized by a specific allelic fre- quency of OXTR rs53576 (heterozygosi- ty: AG). The homozygous GG variant of this SNP is argued to be associated with prosociality, and the AA, on the contrary, with poor sociability. The heterozygous variant (AG) probably is a compromise that enables its carriers to successfully combine high social skills with antisocial behavior (free-riding). This find- ing supports existing evidence on the role of OXTR rs53576 in human social behaviour.