I've always favored brunettes, so I don't have tons of direct experience with goldilocks. But I've noticed that the high school and college girls at '80s night who are most likely to be repeat customers are blonds. That's true during a single night -- to keep coming back to say hiiii, wave whenever they see me again, or when they're leaving, to go out of their way to stop by, reach up to stroke my leg and say byeeee i'll see you laterrrr. It's also true across nights -- to make a little trip to where I am once they recognize me, smile brightly, ask do you remember me????!!?! and hang around for awhile.
Most of the girls who approach me are brunettes, so as a fraction of all girls who come up to me, blonds are especially more likely to get stuck. For guys who are less picky than I am about hair color -- are blonds more bond-oriented and brunettes less? And the same question for girls -- are blond guys more commitment-philic and dark-haired guys more commitment-phobic? (I count very few blond dudes among the pickup artist gurus.)
This is of evolutionary interest since we need to find out why light hair, eye, and skin color rapidly evolved in Northern Europeans. You can spin a physical story about light skin and vitamin D or whatever, but not about light hair and light eyes. Ideally there'd be just one story about lightening color in general, and it's surely behavioral. There are a handful of studies showing that blue-eyed children are more socially nervous, and ditto fair-haired children. But is the fitness benefit accruing to children, e.g. to avoid strangers when they're defenseless? I wonder if it's not just a precursor to their behavior as reproductive-age adults, where they might become more closely bonded to their mate instead of keeping one eye always on other potential flings.