Jessica Wynn

Yeah.

Yeah, not interested.

Yeah, that's hilarious.

But another strong indicator is a fetus's preference for sucking its left or right thumb, like I said.

So the preference is maintained throughout pregnancy, but handedness is thought to be decided before our thumbs even develop.

It's using the ultrasound studies.

Researchers can observe a fetus's earliest arm movements as early as 10 weeks to determine a preference.

So a fetus will often make faster, more precise movements with its dominant arm.

And by 18 weeks, the hand's structure is developed and one side will reach toward their face, mouth, and eyes more.

Cool.

Yeah.

I mean, it's still kind of a chicken and egg problem, though, because we don't know if the fetus is positioned that way because it's predisposed to be left handed or does the position create preference.

Pink, blue, or southpaw.

Please do not invite me to a handedness reveal party.

Yes.

I will not go.

Plus, it wouldn't be 100% accurate because other factors do nudge handedness.

Like hormone exposure, womb space, even your birth order, they all play subtle roles.

Absolutely.

And like we said, when a woman ages, too, so it depends.