Anyways, the statement you quote is no doubt accurate as to the state of the non-white female mind cca 1940, which is when it was made. It happens to also be accurate as to the state of the white female mind cca that same 1940, as forinstance Marylin in any of her "acting"/self-representation endeavous readily attests. Here, have some :

What's the matter with you, anyway?
I'm not very bright, I guess.

I wouldn't say that. Careless, maybe.
No, just dumb. If I had any brains, I wouldn't be with this crummy girls' band.

Well, why'd you take this job?
I used to sing with male bands, but I can't afford it any more. Have you ever been with a male band?

Who, me?
That's what I'm running away from. I worked with six in the last two years. Oh, brother.

Rough?
I'll say.

You can't trust those guys.
I can't trust myself. I have this thing about saxophone players. Especially tenor sax.

Really?
I don't know why, but they curdle me. All they have to do is play eight bars of 'Come To Me, My Melancholy Baby' and I get goose-pimply all over, and I come to 'em.

That so?
Every time.

You know, I play tenor sax.
But you're a girl - thank goodness. That's why I joined this band. Safety first. Anything to get away from those bums. You don't know what they're like. You fall for 'em. You think this is gonna be the biggest thing since the Graf Zeppelin. The next thing you know, they're borrowing money from you, spending it on other dames and betting on horses.

You don't say.
Then one morning you wake up, the guy's gone, the sax's gone. All that's left is a pair of old socks, and a tube of toothpaste all squeezed out, just like your life. You pull yourself together, you go on to the next job, the next saxophone player. It's the same thing all over again. You see what I mean? Not very bright.

Brains aren't everything.
I can tell you one thing. It's not gonna happen to me again - ever. I'm tired of getting the fuzzy end of the lollipop.

Needless to say, her stated dialogue in Some Like It Hot doesn't represent the actual thought process or verbalized output of the female she depicts. The (well meaning, by the way) patriarchy elite confiscated "her" voice (as depicted by her but constructed by them, and broadcast by their wholly owned media) in order to try and disseminate a diffuse sorta "mind bomb"/earworm/whatever you'd call a meme before you call them memes among her ilk. It didn't work, of course, hence all the redditards today ; but that the need was perceived should be sufficient proof to dispose of the point for the needs of this conversation.

Yes you can make people out of women, if you know what you're doing ; yes some rudimentary attempts at reproducing my elaborate educational facilities were somewhat widely deployed (really -- very narrowly ; yet about as over-represented in period media as mine are, it just happens today'd period media === trilema) a century ago.

Rudimentary as they were, nevertheless they were quite expensive and so only ever deployed by rich people, which happened to exclude anyone but the whites at the time, which happens to make it look like there's some kind of skin-tone difference, but let a man who has more experience enslaving women than anyone else ever inform you : it dun matter what color she is. It matters 1. whether you're willing to beat her to death and 2. whether you're willing to pick one in a million.

if it weren't for the tens of thousands of white bums burning off their fat deposits a certain ineffectual way for incomprehensible reasons, the thousands of whores burning off their fats deposits another certain ineffectual way so the hundred of pimps here described could exist at all

As per HL Mencken,

it is impossible to talk anything resembling discretion or judgment to a colored woman. They are all essentially child-like, and even hard experience does not teach them anything.

That might have had something to do with it also.