Читать книгу The Complete Parenting Collection - Steve Biddulph, Steve Biddulph - Страница 43

 In the animal kingdom, one kind of hyena – the spotted hyena – is born with so much testosterone that even the female pups have a pseudo penis and their labia resemble testicles. The pups are born with a full set of teeth, and are so aggressive that they often eat each other within a day or two of being born!

 In a rare condition of boy babies, which is found in the Dominican Republic, testosterone does not take effect in the womb because of a missing enzyme. These boys are born without a penis or testicles – looking in fact more like girls, and raised as such. But at about twelve years of age, testosterone is produced in their body and the boys suddenly develop into ‘real’ boys, growing a penis and testicles, getting a deep voice, and so on. They apparently then live normal lives as men. They are known as ‘penis at twelve’ children.

 A condition called Congenital Adrenal Hyperplasia can give girls excess testosterone in the womb, but this is remedied once the child is born. Although they are hormonally normal from then on, these girls show above-average athletic skills, as well as a preference for male playmates, toy cars and guns, and ‘masculine’ clothes.

 An excess sensitivity to testosterone, or an excess of it, has been linked significantly to mathematical ability, left-handedness and a very high incidence of asthma and allergies.

 Estrogen – the female counterbalancing hormone to testosterone – has been shown to cause nerve cells to grow more connections. Females have smaller brains, but these are better connected!

 Baritone singers in Welsh choirs have more testosterone than tenor singers. Baritones are also more sexually active!

 Making love raises your testosterone level. The more you get, the more you want – at least for a couple of days! Winning at sport or politics also raises your testosterone level. Stress and loneliness lower it: they lead to more estrogen being produced so you can cope like a woman!

 One final testosterone fact – perhaps the most amazing of all – illustrates the intricate dance between biology and behaviour in the development of higher animals. Are you ready? Here goes …

Mother rats frequently lick the genitals of their male babies, and this helps the latter’s brains to become fully male. And guess what? It’s the presence of testosterone in the urine of the baby male rats that seems to trigger the behaviour. If baby female rats are given testosterone injections, the mother licks their genitals, too! If baby boy rats are castrated, the mothers don’t lick them any more (a double tragedy!).

But wait, it gets more amazing. The rats that are licked in this way develop a masculine-functioning pituitary gland, whether they are male or female. Female rats given the licking treatment behaved like male rats for the rest of their lives. And when the licking was replaced by a researcher stroking the male or female rats with a paintbrush each day, the same long-term physical changes to the brain took place.

Of the hundreds of studies I have seen, this one probably tells us more about how complex the interaction is between nature and nurture in developing gender characteristics. (And that is perhaps the only conclusion we can draw from it!)

There are physical and social influences at work all the time, in complex interaction, to produce healthy and functioning males and females. Gender differentiation does not just happen automatically. Without affection and stimulation, we know children don’t grow as well or become as intelligent as their potential would allow. We have to bring nurturing and parenting skills to bear, to help our kids both develop physically and find a comfortable gender identity.