Why does junior get such a kick...

Why does junior get such a kick out of braining his sister (often with her own dolls)? Why do men commit 90% of the world’s violent crimes? Are they everywhere brought up in environments that teach them aggressive behavior?

Or are men (generally bigger, faster, stronger, more aggressive and more physical) and women (generally more nurturing, socially oriented and more verbally skilled) prisoners of their own biology or genetic inheritance?

“The Sexual Brain,” part of KCET’s locally-produced “California Series” (Channel 28, tonight at 7:30), doesn’t presume to supply any final answers to the old nature/nurture controversy or end the eternal battle of the sexes.

But it addresses the subjects in its snappy, provocative look at the sociocultural implications of new evidence that shows that the brains of men and women are considerably different--anatomically, chemically and in how they function.

An anthropologist, for example, theorizes that because males and females have pursued different reproductive strategies over the evolutionary eons, no mammal--rat or human--will ever be found in which male and female brains will be the same. Evidence backs him up.

Another scientist emphasizes the masculinizing effects male hormones can have on females: normally, for instance, male songbirds sing and females don’t; but if female birds are given male hormones, they grow up and chirp like Whitney Houston. Other studies show that human females exposed to male hormones think and act more masculine.

Packed with information and thoughtfully written, the show (repeated Sunday at 11 p.m.) was produced by Teya Ryan and Roger Bingham, who doubles ably as host.