Girls are hitting puberty earlier and earlier, with breast development as early as age 7! This news has upset many people, but it may make evolutionary sense in some cases for girls to develop faster, according to the authors of a recent study.
The US-based study found that girls who physically mature earlier tend to start dating, have sexual intercourse at a younger age, and have more sexual partners than girls who develop later. That puts them at risk of sexually transmitted diseases and makes them more likely to have a child while they're still teenagers.
These are generally seen as bad things, say the authors, given that many psychologists and doctors think there are right and wrong ways to develop. But they say it makes more sense to look at development the way nature does from an evolutionary perspective. This leads to the expectation that growing up in a risky, unstable environment - the kind that fosters an insecure rather than secure attachment of infant to mother - should accelerate pubertal maturation thus increasing the chances that one could reproduce before they die.
The study experiments showed that babies who smiled, vocalised, reached, or otherwise demonstrated appreciation that their mother was back were considered to be secure; those who avoided their mother following the separation or could not be comforted by her return were considered insecure. Results also revealed, as predicted, that girls who were insecure as babies started their pubertal development sooner, by about two to four months, than girls who were secure as babies. They also completed pubertal development sooner and had their first period earlier than girls who were secure as infants.
However, a risky, unstable early environment, as reflected in an insecure attachment, is not the only reason girls mature early; it's also partly due to genetics. Environmental chemicals may also have some effect. Also, there's been a trend over the last 150 years of girls maturing earlier, possibly because of improved nutrition. But the early rearing environment and the infant-mother attachment relationship are important influences and should not be ignored, say the scientists.
|
