Genetic factors and adults' expectations towards relationships interact in affecting physiological responses to social distress

Distinct expectations towards interaction with conspecifics and genetic predispositions differently affect adults’ social behaviours. However, the underlying mechanisms remain largely unknown. Here, we hypothesized an interaction between genetic factors (oxytocin receptor, OXTR, and serotonin transporter, 5-HTTLPR, gene polymorphisms) and adult interactional patterns in shaping physiological responses to social distress. During the presentation of distress vocalizations (human female, infant and bonobo cries) we assessed participants’ (N=42 males) heart rate (HR) and peripheral nose temperature, which index state of arousal and readiness to action. Self-reported questionnaires were used to evaluate participants’ interactional patterns towards peers (Attachment Style Questionnaire, Feeney et al., 1994), and the quality of bond with intimate partners (Experiences in Close Relationships Scale, Fraley et al., 2000). To assess participants’ genetic predispositions OXTR gene (regions rs53576,rs2254298) and 5-HTTLPR gene (region SLC6A4) were genotyped. Analysis revealed a significant Gene X Environment interaction. S carriers in 5-HTTLPR gene(related to lower reactivity to external social stimuli) with high need for approval from peers and high abandonment anxiety towards partners showed HR increase in response to cries. Whereas, GG homozygotes in rs53576(related to higher sociality) with higher abandonment anxiety showed HR decrease. Furthermore, GG homozygous in rs53576 and A carriers in rs2254298 (related to higher sensitivity to environment) when reporting lower fear of intimacy with peers showed nose temperature decrease in response to cries. Findings highlight that the interaction between genetic factors and social expectations by shaping physiological activations, indirectly contribute in shaping individuals’ social adaptiveness and well-being in distressing social situations.