2026-03-30
2 小时 11 分钟The larger the number of older brothers that a male has, the higher the probability that he is gay.
It's been seen over and over.
I mean, it's really one of the rock-solid findings in human sexuality.
So the way to emphasize the difference is if a baby boy is born today.
If he has no older brothers, his odds of being gay when he grows up is about 2%, right?
Pretty low.
But if he had one older brother, his odds go up by a third.
Okay, 2.6.
And if he has two older brothers, they go up a third again.
All right, now we're at 3.5.
It turns out you've got to have like a dozen older brothers just to have a 50-50 chance.
Welcome to the Huberman Lab Podcast, where we discuss science and science-based tools for everyday life.
I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine.
My guest today is Dr. Mark Breedlove.
Dr. Mark Breedlove is a professor of neuroscience at Michigan State University,
and he is an expert in how hormones shape the developing brain, in particular, how they influence sexual orientation.
As you 'll learn today, the amount of testosterone that a fetus is exposed to while in the mother has a profound impact not
only on the ratio of finger lengths, yes, you heard that right,
but it also plays a meaningful role in sexual orientation.
And in fact, there's a correlation there between finger length ratios and sexual orientation.