Board Thread:WARNING ALL USERS False Info\Spoilers/@comment-108.81.117.0-20140115224300/@comment-19765459-20140115224710

It's like anything in life. There self-control or loss of self-control. Much like people who are compulsively violent (e.g. almost every Hunter we've seen). Scott feared shifting because doing so physically takes him further away from his sense of human self-identity, which in turn might make him lose himself like Malia did.

This is probably less of an issue for born-werewolves, who spend their whole lives with a clear sense of their human and bestial natures coexisting.