In Kasparov's eventual defense, he did say this after losing to Polgar:

“I was wrong about women playing chess. I gave an opinion a long time ago that I no longer believe.”

and later in his book wrote:

‘I won’t hide from the fact that I did make regrettably sexist remarks about women in chess around this time. In that 1989 Playboy interview I said men were better at chess because “women are weaker fighters” and that “probably the answer is in the genes”. The possibility of gender brain differences aside, I find it almost hard to believe I said this considering that my mother is the toughest fighter I know.’