Oxytocin facilitates social approach behavior in women.

Katrin Preckel,Dirk Scheele,Wolfgang Maier,Keith M Kendrick,Renã© Hurlemann

doi:10.3389/fnbeh.2014.00191

Abstract

In challenging environments including both numerous threats and scarce resources, the survival of an organism depends on its ability to quickly escape from dangers and to seize opportunities to gain rewards. The phylogenetically ancient neurohormonal oxytocin (OXT) system has been shown to influence both approach and avoidance (AA) behavior in men, but evidence for comparable effects in women is still lacking. We thus conducted a series of pharmacological behavioral experiments in a randomized double-blind study involving 76 healthy heterosexual women treated with either OXT (24 IU) or placebo intranasally. In Experiment 1, we tested how OXT influenced the social distance subjects maintained between themselves and either a female or male experimenter. In Experiment 2, we applied a reaction time based AA task. In Experiment 3 we investigated effects on peri-personal space by measuring the lateral attentional bias in a line bisection task. We found that OXT specifically decreased the distance maintained between subjects and the male but not the female experimenter and also accelerated approach toward pleasant social stimuli in the AA task. However, OXT did not influence the size of peri-personal space, suggesting that it does not alter perception of personal space per se, but rather that a social element is necessary for OXT's effects on AA behavior to become evident. Taken together, our results point to an evolutionarily adaptive mechanism by which OXT in women selectively promotes approach behavior in positive social contexts.

Highlights

For humans as with all social species, approach behavior has a pivotal function in signaling interest in conspecifics, thereby providing a means to establish and cultivate close relationships (Baumeister and Leary, 1995)
The female participants maintained a larger distance between themselves and the experimenter if the latter avoided eye contact (EC), and the interaction was qualified by a larger distance if the experimenter instead of the subject was moving in trials with a far starting position” (SP)
OXT decreased the social distance that female participants kept between themselves and an unfamiliar attractive and friendly male experimenter in Experiment 1 and accelerated the motor responses toward pleasant social scenes in Experiment 2

Summary

Introduction

For humans as with all social species, approach behavior has a pivotal function in signaling interest in conspecifics, thereby providing a means to establish and cultivate close relationships (Baumeister and Leary, 1995). Another study utilizing a reaction time based AA task observed that OXT diminished the differential response to angry and happy faces in men (Radke et al, 2013) These findings are in stark contrast with the results of another study reporting an accelerated response selectively for disgusted facial expressions (Theodoridou et al, 2013) and where the authors propose that OXT may play a role in behavioral prophylaxis. This latter interpretation resonates well with previous findings of enhanced defensive reactions after OXT administration (Striepens et al, 2012; Grillon et al, 2013). It appears OXT can promote approach behavior in men, but only under certain circumstances and with heightened caution (Striepens et al, 2012)

Methods

Results

Conclusion