It has a lot of good ideas that are probably true, although some are rediscovering things psychology had found out long ago.

Actually you know what can cause big personality change? A good plastic surgery/facial correction. I heard it's actually one of the few things that can do that. And a positive one, too; towards more confidence and extrovertedness (if you think it's 'positive'), a trait most psychologists considered fixed in any other cases. But I can't find the source right now, or if I even heard it. But it makes perfect sense to me. Like a good jaw realignment that fixed your whole face, blaw, suddenly you're this other person.