Smells Like Dad

Two recent studies explore the links between the age at which girls reach puberty and the presence of adult males in the home. Writing last summer in the Journal of Personality and Social Psychology, a team of five scholars looks at the factors that seem to delay the onset of puberty in girls. What are they? The presence in the home of the biological father. A father who demonstrates warmth and love. And a close relationship between the mother and father. Overall, “the quality of fathers’ investment in the family emerged as the most important feature of the proximal family environment relative to daughters’ pubertal timing.” Regarding the implications of these data, it appears that “early pubertal maturation, risky sexual behavior, and early age of first birth are all components of an integrated reproductive strategy that derives, in part, from low paternal investment.”

Why would the father-daughter bond emerge as the key factor? The researchers speculate that it may have something to do with the daughter’s exposure to her father’s “pheromones.” Pheromones are chemical substances secreted by the body that serve as stimuli to others of the same species for one or more behavioral responses. English translation: Her father’s aura slows down her sexual maturation. A related hypothesis is that “low levels of positive family relationships,” especially in conjunction with “exposure to unrelated adult males,” serve as “causal mechanisms” for earlier puberty.

Which brings us to the second study. Writing in the March/April issue of Child Development, two scholars (one of them, Bruce J. Ellis, was also involved in the earlier study) seek to isolate the factors that speed up the onset of puberty. One is the absence of the biological father. Another is maternal depression. But even more significant is the presence in the home of an “unrelated father figure” - that is, a stepfather or mother’s boyfriend. The younger the girl at the time of the unrelated male’s arrival in the home, the earlier the onset of puberty.

What explains this finding? The presence of stepfathers and boyfriends in the home is associated with greater levels of stress, dysfunction, and interpersonal conflict. Also, we’re back again to those pheromones. For it seems that, while a father’s aura slows down the girl’s sexual development, the aura of an unrelated male has exactly the opposite effect.

Let’s sum up. If we want young girls to delay sex and childbearing, having a loving biological father on the premises is a good idea, while having unrelated men on the premises is not. The folk wisdom that we in this generation learned from our grandmothers, and then largely rejected, is looking better all the time.

Sources: Bruce J. Ellis, et. al., “Quality of Early Family Relationships and Individual Differences in the Timing of Pubertal Maturation in Girls: A Longitudinal Test of an Evolutionary Model,” Journal of Personality and Social Psychology 77, no. 2 (August 1999): 387-401, Bruce J. Ellis and Judy Garber, “Psychosocial Antecedents of Variation in Girls’ Pubertal Timing: Maternal Depression, Stepfather Presence, and Marital and Family Stress,” Child Development 71, no. 2 (March/April 2000): 485-501.

First published Spring 2000.