Other factors that are known to cause early puberty, such as genetics and nutrition, were not looked at. Puberty is starting younger and younger with each generation, according to Hadine Joffe, MD, who is director of the Women's Center for Behavior Endocrinology at McLean Hospital at Harvard Medical School. Joffe, who reviewed the study for WebMD, says the findings are an interesting evolutionary hypothesis. The nature or nurture issue came up in the study when the authors noticed the correlation between the age of the daughter when the father left the household, and the exposure to either a stepfather or the mother's boyfriend. The researchers theorized that the influence of unrelated males on puberty could be due to pheromones.
Pheromones are hormones that are thought to stimulate, through smell, sexual reactions in animals.
Of course, he says, one has to be careful not to make broad associations that could have wide-range implications. More research needs to be done on the senses before this conclusion is reached, he says. Both Joffe and Licht say that the one aspect of the study that may have relevance is the issue of maternal depression. While Ellis himself says that this study is simply observational and no clinical conclusions can be drawn, Joffe and Licht think that the issue of a mother's or any family member's depression having an effect on family dysfunction can be a real message. A therapist could act as a mediator to help the mother and daughter maintain a functional relationship.