Until now, the trend in the ever decreasing age of puberty in girls has been attributed to increased body weight.

A recently released study from the University of California, Berkeley, however, is now saying that the presence or absence of the girl’s biological father has some influence over the age at which she goes through puberty.

Girls whose biological father was not living at home began to develop earlier than girls whose fathers lived at home with them.

Interestingly, this link was only seen in higher income families and particularly in African American families according to Medical News Today.

The researchers are still not sure of the reasons for these findings but Julianna Deardorff, UC Berkeley assistant professor of maternal and child health, speculated: “it’s possible that in lower income families, it is more normative to rely upon a strong network of alternative caregivers.

“A more controversial hypothesis is that higher income families without fathers are more likely to have a single mother who works long hours and is not as available for caregiving. Recent studies have suggested that weak maternal bonding is a risk factor for early puberty.”