eli5: What determines if one’s bellybutton will be an innie or an outtie?


Is it genetic? Or does it have to do with the procedure of cutting the umbilical cord?

In: 8

Pretty sure it’s genetic. I used to get so tickled at how deep my dad’s belly button was- I could sink almost a whole Q-tip in it. Now, as an adult, my belly button is just as deep.

I have also seen a few outies that are shared by mother and daughter/ father and son, etc.

However, supposedly, it all comes down to whether a newborn had a bit of space between their abdominal wall and their skin- if they don’t, then they get stuck with an outie. Outies only happen in 1 in 100 people.

Still, there’s got to be some genetic connection to this.


Oh and apparently, an outie can become an innie, with plastic surgery. =)