Dan Gilbert: Why are we happy? [video]

A lot of this has already appeared in the popular press, but this is a lecture by a Harvard psychologist responsible for much of the research. He's funny & punchy, and generally quite enjoyable to watch.

Aside from the experiments, I thought the bit about how freedom was the enemy of happiness was pretty interesting. Among other things, it explains the reaction to PG's essays: in order to maintain their happiness, they have to believe that they're stuck in a boring corporate job and have no other options. Otherwise, they have a choice, and with that choice comes regret, and with regret comes unhappiness. So PG is really spreading unhappiness the world over. ;-) His essays only resonate with those who already know they have a choice, because we're not going to become more unhappy about it, and it might inspire us to actually try it.

Also explains why the 20s can be such an emotional wasteland - coming out of college, we have so many possible choices, and nearly all of them are reversible.