If there's anything that's true about recent films, it's that they are coming closer and closer to explaining the real instincts that are so different between men and women. Maybe it's only those by the director of Wedding Crashers and the writers of The Hangover. Either way, the just-released movie, The Change-up sends a single man and married man into the other's role, with disastrous, but truly enlightening consequences no matter which you are in your own life.