Document Type

Article - postprint


Psychology (Pitzer)

Publication Date



sex differences, neonates, infants, prenatal testosterone, developmental systems


Sex differences in infants warrant attention, not because they clarify the extent to which such differences reflect nature or nurture, but because studying them is likely to illuminate the origins of sex differences later in life and thereby yield manipulations that could influence the development of important competences. It is not yet clear how male and female infants come to differ. Testosterone is influential, but because of the complexity of the developmental systems in which it operates, its effects are not straightforward: Testosterone does different things in different contexts. Simple explanations invoking hormone exposure should not be expected to satisfactorily answer questions about the origins of sex differences, but standardizing protocols to allow meaningful meta-analyses would help bring coherence to the research literature in this domain.


This article was written with the support of the Research and Awards Committee of Pitzer College. I am grateful for the support and help provided in connection with this project by Melissa Hines and Dawn Moore.

The content of this open-access post-print article is the same as that contained in the published article with the following reference:

Moore, D. S. (2012). Sex differences in normal fetuses and infants: A commentary. Child Development Perspectives, 6, 414 – 416.

Rights Information

© 2012 David S. Moore. Child Development Perspectives. © 2012 The Society for Research in Child Development.