Testosterone on My Mind and in My Brain

Simon Baron-Cohen discusses the role of prenatal testosterone in shaping the mind and brain. He begins by noting typical sex differences in neuroanatomy (e.g., male brain ~8% larger, more synapses, more gray/white matter) and psychology (females faster empathy development, males stronger systemizing). To investigate biological roots, his lab conducted a newborn study showing that 24-hour-old girls look longer at faces and boys at mechanical objects. They then used amniocentesis samples to measure fetal testosterone and followed 500 children longitudinally. Results showed that higher prenatal testosterone correlates with less eye contact at age 1, smaller vocabulary at age 2, lower empathy at age 4, and stronger systemizing interests. MRI scans at age 8 revealed testosterone-related differences in brain structures like the planum temporale and corpus callosum. The research also links prenatal testosterone to autistic traits, and a larger Danish biobank study is investigating direct links to autism diagnosis. Baron-Cohen discusses ethical implications, the interplay of genes and environment, and the ongoing question of whether autism should be prevented or cured. Q&A covers topics such as animal models, genetics, environmental factors, and the concept of 'extreme male brain'.