There is no doubt that Golding spoke these words, perhaps more than once.
A clip preserved on YouTube, in which Golding discusses the origins and meaning of Lord of the Flies, captures him making that pronouncement, specifically in answer to the question of why his dystopian novel featured boys rather than girls:
Girls say to me, very reasonably, ‘why isn’t it a bunch of girls? Why did you write this about a bunch of boys?’ Well, my reply is I was once a little boy — I have been a brother, a father, I am going to be a grandfather.
I have never been a sister, or a mother, or a grandmother. That’s one answer. Another answer is of course to say that if you, as it were, scaled down human beings, scaled down society, if you land with a group of little boys, they are more like a scaled-down version of society than a group of little girls would be.
Don’t ask me why, and this is a terrible thing to say because I’m going to be chased from hell to breakfast by all the women who talk about equality — this is nothing to do with equality at all.
I think women are foolish to pretend they are equal to men, they are far superior and always have been. But one thing you can’t do with them is take a bunch of them and boil them down, so to speak, into a set of little girls who would then become a kind of image of civilisation, of society. The other thing is &mdashl why aren’t they little boys AND little girls?
Well, if they’d been little boys and little girls, we being who we are, sex would have raised its lovely head, and I didn’t want this to be about sex.