It is now generally accepted that some people are more altruistic, more trusting, or more reciprocal than others, but it is still unclear whether these differences are innate or a consequence of nurture. We analyse the correlation between handedness and social preferences in the lab and find...

We examine whether social preferences are determined by hormones. We do this by investigating whether markers for the strength of prenatal testosterone exposure (finger length ratios) and current exposure to progesterone and oxytocin (the menstrual cycle) are correlated with choices in social...

We study how the work effort and output of non-migrants in a village economy are affected when a member of the village population migrates. Given that individuals dislike low relative income, and that migration modifies the social space of the non-migrants, we show why and how the non-migrants...