Wow, it's the "really cool little things" that make articles like this so interesting. I just learned of “cryptophasia”... a secret language that twins share as

Wow, it's the "really cool little things" that make articles like this so interesting. I just learned of “cryptophasia”... a secret language that twins share as kids. While scientists question whether cryptophasia constitutes a discrete language, they agree it offers a provocative look into the birth and development of language itself. If one sees a copy of one's self, does one learn to recognize the other's state based on theory of mind and proprioception? Huh. Very interesting.