Men and Women are different – obviously so in size, anatomy and sexual function. But some scientists now believe that they are unike in more fundamental ways. Men and Women seem to experience the world differently, not merely because of the ways they were brought up in it, but because they feel it with a different sensitivity of touch, hear it with different aural responses, puzzle out its problems with different cells in their brains.

Hormones seem to be one key to the difference – and an emerging body of ividence suggests that they do far more than trigger external sexual characteristics. They actually “masculinize'' or “feminize'' the brain itself. By looking closely at the fundamen- tal processes involved, investi- gators are finding biological explantations for why boys play more roughly than girls. Whether these pshysiological differences destine men and women for separate roles in society is another and far more delicate question. The particular way brains are organized may orient them towards visual spatial perception, explaining – perhaps – why they seem superior at mathematics.

Women's brains may make them more verbally disposed, explaining possibly why they seem more adept at languages. Males of most species appear to be hormonally primed for aggression, pointing – it may be – to the long evolutionary record of male dominance over women. But few of these presumed differences go unchallenged. And whether they imply anything more – about leadership capacities, for example, or that men are biologically suited for the workplace and women for the hearth – is another part of the thicket. The notion that biology is destiny is anathema to many researchers. To them, sexual stereotyping reinforced by a male-dominated culture, has more bearing on gender behaviour than do hormones.

“As early as we find sex differences among babies, we find the culture acting differently towards them'' insists Michael Lewis of the study of Exceptional Children.

Nature vs Nurture :-

The new research has thus revived, in all its intensity, the debate over whether “nature'' or “nurture'' plays the greater part in male-female behaviour. But beneath all the chaims and counterclaims, the sex research- ers are providing fascinating new glimpses into the biology of behaviour. It is widely agreed, for example, that in the majority of animal species, males are more prone to fighting than are females. Biologists trace this to the hormone testosterone, secreted in the testes of the male foetus during critical period in its development.

In 1959, American physiologists Charles Phoenix, Robery Goy, Arnold Gerall and William Young conducted still considered a landmark. When they injected pregnant guinea-pigs with massive doses of testosterone, the genetically female offspring in the brood had both ovaries and male genitalia. When the ovaries were removed and the aberrant females were given a fresh dose of testosterone, they behaved like males, even mounting other females – the gesture of male dominance in many species. Goy has confirmed the effects of testosterone in experiments with rhesus monkeys. Not only is female behaviour partly masculinized by pre-natal testosterone, but the robustness and vigour of males depend on how long prior to birth they have been exposed to the hormone. To see if hormones play a similar role in human behaviour,

John Money studied one of nature's own experiments – children exposed to abnormally high levels of androgens (male hormones) before birth because of adrenal-gland malfunctions. Among other effects, the researchers found that girls born with this disorder exhibited distinctly “tomboyish'' behaviour, seldom played with dolls and began to go out with boys at a larger age than other girls.

The much-cited Money-Ehrhardt research has provided a classic context for the nature-nurture debate. Some scientists maintain that the tomboyish was a clear result of the hormone exposure, and bolster their argument by noting the scores of animal experiments that demonstrate similar effects.

Other criticize the study for failing to emphasize that girls with congenital adrenal hyperplasia do not look like normal female genitals. Thusm they may be treated differently as they grow up, and their behaviour could be more the result of an abnormal environment than of a abnormal blood chemistry.