Inhumane behavior often comes from having damage to prefrontal cortex, leading to bad self-control and moral reasoning. But brain damage is not a mechanism for becoming a genius. Basically there is no reason for the two to be correlated.

Maybe you need counterexamples?

Darwin: Devoted family man, not known to be a perv. Went out of his way to give joint credit to Wallace for the theory of natural selection. An asshole wouldn't do that.

Einstein: big pacifist. Worried like hell about war. Generally thought to not be an asshole. However, he was said to cat around a bit in his youth. http://en.wikipedia.org/wiki/Albert_Einstein

Benjamin Franklin: definitely not an asshole. Came up with bifocals, showed that lightning was made of electricity, and thought of the ideas of positive and negative charge. Liked to cat around. Not a known perv, unless you somehow count the fur hat he wore when visiting France.

One of the problems is that it's easier to remember stories about geniuses who were assholes or freaks. Pablo Picasso (despite the song), Vincent Van Gogh, Isaac Newton. Maybe the myth comes from the fact that geniuses sometimes think that they don't have to follow other people's rules. Kind of like the very rich and very powerful.

Oh yes, ha ha, except! That nihilistic asshole you put up with until you realized he wasn't even actually smarter than you: neither rich nor powerful. Carry on!

He thinks Naipaul subject his mistress to a "species of soul murder," and that the book will destroy his reputation. What becomes of a widely-accepted genius who is later proven to be a colossally horrible person? Wrong question to ask, guys!

So, to put you in the mood, is a story the Washington Post ran back when he won the Nobel in 2001 after writer Linton Weeks had tea with Naipaul and his fourth wife Nadira Alvi

He has never had children. "Never wanted any," he says in his
tea-with-cream tone. His first wife probably did want kids "at some
stage," he says, but "the thought was very disagreeable to me."

Laughing, Alvi tells of Naipaul seeing a baby in a carriage not too
long ago. He pointed and exclaimed, "Look, look, look! What an ugly
little brute!"

The mother, Alvi says, was mortified.

She holds this up as an example of her husband's wit.

"Quality of wit is something that is with someone all the time," Naipaul says.

He offers two more examples of his wittiness: Novelist and critic
Elizabeth Hardwick once asked him why Indian women wear the bindi mark
on their foreheads. He told her: "It means, 'My head is empty.' "

Naipaul and wife laugh and laugh.

Okay, so also in that story, Naipaul is quoted saying he didn't know why he had been awarded that particular year. "It remains a mystery. I think that perhaps the prize had run a little bit into, kind of, the doldrums." See, he'd sort of given up on winning in 1988, when he said: "Of course I won't get it - they'll give it to some nigger or other." He grew up in Trinidad, which he also blames for his lifelong distaste for music.

After years of using prostitutes, the turning point in Naipaul's life comes in 1972 when he finds a woman he desires: Margaret, whom he has met in Buenos Aires. She apparently refused to be interviewed for the book, but her archived love letters supply the missing narrative. They are rapturous, despairing, pleading, speaking of "his cruel sexual desires". She acknowledges that he is her black master, that he regards his penis as a god, that she will worship it, abase herself.

This word "master", used often in the letters, is interesting. It is a slave word. In role playing - and most of these love letters refer to highly eroticised power games - the master is regarded as dominant; but, paradoxically, it is usually the submissive person, the masochist, who has the ultimate power - maddening for the sadist.

Here is one instance. Margaret shows up unexpectedly in Wiltshire. Naipaul is displeased with her. He beats her and afterwards explains, "I was very violent with her for two days with my hand; my hand began to hurt . . . She didn't mind at all. She thought of it in terms of my passion for her. Her face was bad. She couldn't appear really in public. My hand was swollen."

"Margaret was Vidia's ideal woman," French writes. "He could string her along and mistreat her with her abject consent." He later writes, in paraphrase, "She said she had done things to Vido that would have made her sick with anybody else, and yet she longed for the time when she could do them again." It is no exaggeration to describe the relationship between Naipaul and Margaret as a version of The Story of O.

Eventually Naipaul told his wife Pat about the relationship, divulging some details and showing her intimate photographs. She was devastated but stayed with him and he was reluctant to offer a divorce. He gave her literary jobs to do, went on reading his rough drafts of his fiction to her - in which the sex scenes were based on the rough sex he enjoyed with Margaret.

And here's some more of that Post story:

He offers two more examples of his wittiness: Novelist and critic
Elizabeth Hardwick once asked him why Indian women wear the bindi mark
on their foreheads. He told her: "It means, 'My head is empty.' "

Naipaul and wife laugh and laugh.

Another time he was conducting an interview on the radio and he asked
an author a question. The author answered it. "Laudable, most
laudable," Naipaul said. "Now coming back to your wretched book . . ."

Naipaul and wife laugh.

...
He does cry. When he watches old movies like "High Sierra." And the
scene in "The Roaring Twenties" when James Cagney is dying and Gladys
George says, "He used to be a big shot."

One morning Alvi heard her husband weeping as he woke up. He was
remembering how hard it had been to get a start as a writer.

He likes for Alvi to read to him. She will pick up a book by her
husband and read aloud. "He's amazed by what he's written," she says.

And sometimes he's so moved, he cries.

I know, I know, I kind of want to read his books now too! Good thing I am lazy.

Paul Theroux claims new biography reveals monster inside V.S. Naipaul [Times of London]