Little evidence that androstadienone affects social distance-dependent prosocial behaviour: a pre-registered study

In navigating the complexities of social life, humans have evolved to interpret invisible odorous chemical cues, with profound behavioural impacts often unbeknown to the conscious mind. The manifestation of this in humans is evident in the scent of androstadienone (androsta-4,16-dien-3-one), an odorous compound which is considered a putative human pheromone. The current study investigated the effect of androstadienone on social distance-dependent prosocial behaviour measured by a social discounting task, in which participants chose between selfish and generous options. Based on our pre-registration, we predicted a sex-specific effect, with males exposed to androstadienone exhibiting increased generosity, while females would choose more selfishly. Employing a double-blind, placebo-controlled, between-subject design, we recruited 170 participants who were randomly assigned to either the androstadienone or control condition. Olfactory stimuli were administered while participants completed the social discounting task. Inconsistent with our hypothesis, inhaling androstadienone did not impact social distance-dependent prosocial behaviour. This finding was supported by multiple estimates of prosociality, including model-free, model-based and maximum likelihood estimation. Further analyses indicated that androstadienone administration did not influence perceived social distance or bias participants towards being generous or selfish. Thus, our empirical findings provide no support for the hypothesis that androstadienone modulates generosity.