Researchers asked college women, “Ideally, how many children would you like to have?”, and either (a) assessed their peak estrogen levels by collecting weekly urine samples for 4-6 weeks (Study 1), or (b) asked strangers to rate how feminine (vs. masculine) the women’s faces were (Study 2; note: prenatal and pubertal estrogen feminizes faces). Women with higher peak levels of estrogen, or with more feminine faces, reported wanting more children.
Smith, M. J. L., Deady, D. K., Moore, F. R., et al. (2012). Maternal tendencies in women are associated with estrogen levels and facial femininity. Hormones and Behavior, 61, 12-16.
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