Sex and Stress Hormones Across Development: A Focus on Early Behavior

Sex and stress hormones play a vital role in human biological and behavioral development, especially during the first five years after birth. Sex hormones (e.g., androgens and estrogens) are involved in sexual differentiation and have downstream effects on gendered behaviors. Stress hormones (e.g., cortisol) prepare the fetus for the postnatal environment and continue to interact with the environment after birth. This article reviews the contribution of sex and stress hormones to early psychological development, highlighting hormone measurement and its implications for scientific inferences. The article closes by presenting key opportunities for future work.