Sigma?

I finally caught up with a buddy of mine after years and we hung out. Sometime in the middle of the night he called himself a sigma male. And referred someone else as alpha. Someone he's not fond of.

I didn't want to counter anything at that time so I let it slide and moved on to a different topic.

Now I am wondering if sigma male is another trp mumbo jumbo. I don't know anything about it.

Also should I try to tell him to come out of that mindset, if so how should I approach it.

P.s. he's a good person and I think he's fairly liberal and respects women.