Avoidant

His avoidant tendencies led him to isolate himself.

Then as the cranes, that to Riphæan mountains Might fly in part, and part towards the sands, These of the frost, those of the sun avoidant, One folk is going, and the other coming,

But unlike schizoids, with whom they are sometimes confused, avoidants are actually eager to socialize. The reason they hang back is their worry that they are personally unappealing[…]