I have a theory.
But I really have no way to test it. So I figured I'd share it with you all here, and if anybody has had a contradictory experience, you'll tell me.
Here it is:
The more years that heterosexual people spend living independently as an adult (before they move in with a partner), the less likely they are to assume traditional gender roles within a household when they do move in with a partner.
In other words, if a man has to cook and clean for himself for 5+ years, if he decides to move in with a woman after that time, he won't just unlearn his 5 years of cooking and cleaning. The guy will still whip up a mean lasagna and chicken noodle soup as often as he did before. And conversely, if a woman has to change lightbulbs, wash her car, and take out the trash for 5+ years, it's not likely that she'll suddenly stop doing it if she decides to move in with a man.
So then, as the average age in which people get married increases, does the gendered difference in household participation decrease proportionally? (Not that people aren't living together without getting married...but in general...)
The things that occupy my mind on otherwise quiet Sunday mornings...