I've known loads of guys who are have behaviors this place would describe as beta, but women throw themselves at them due to them being tall, handsome and masculine looking. A guy who is ugly but very alpha is still getting nothing. Sure you have to have some social skills and be able to escalate to sex but it's all about the looks.

So Alpha just means tall masculine and good looking Beta is every other guy.

Behavior is interpreted and perceived differently from others based on looks (Halo effect)