Empathy involves an understanding of what others are thinking and feeling, and enables us to interact in the social world. According to the Empathizing-Systemizing (E-S) theory, females on average have a stronger drive to empathize than males. This sex difference may in part reflect developmental differences in brain structure and function, which are themselves under the influence of fetal testosterone (fT) Previous studies have found that fT is inversely correlated with social behaviors such as eye contact in infancy, peer relationships in preschoolers, and mentalistic interpretation of animate motion. Male fetuses are exposed to higher levels of testosterone than are female fetuses. The present study investigates empathizing in children, as a function of amniotic measures of fT. One hundred ninety-three mothers of children (100 males, 93 females) aged 6-8 years of age completed children's versions of the Empathy Quotient (EQ-C), and the children themselves were tested on "Reading the Mind in the Eyes" Task (Eyes-C). All mothers had had amniocentesis during the 2nd trimester of pregnancy. There was a significant negative correlation between fT and scores on both measures. While empathy may be influenced by post-natal experience, these results suggest that pre-natal biology also plays an important role, mediated by androgen effects in the brain. These results also have implications for the causes of disabilities involving empathy, such as autism spectrum conditions, and may explain the increased rate of such conditions among males.