The first interesting fact about happiness is that it doesn't change as much as you think. And one way to look at it is, you have a set point. Just as with regard to possibly weight, temperament, or intelligence, there is a heritability of happiness. So there's a genetically determined range of how happy you're likely to be. And we see this for instance, in that, identical twins raised apart in very different environments tend to be similarly happy. And this to some extent is common sense, some people are naturally cheerful, and positive, and joyous. Others are more reticent, and maybe glum and less happy. This doesn't mean that a miserable person can't achieve great happiness, or a very happy person can't become glum. But just as with other psychological traits, it does mean that to some extent, there are powerful influences on us even before we're born, happiness is heritable. Now, an immediate, very sensible response to this is, what about life events? Certainly, life events will change your happiness one way or another. And think of it as, what's the worst thing that could happen to you? Imagine that for a second, and then ask, how much would it change your happiness? Then ask, what's the best thing that can happen to you? And ask, how much would it change your happiness? It turns out that the answer's somewhat surprising. There have been studies looking at response to different life events including becoming a paraplegic in an accident. Winning an enormous sum of money. [SOUND] For professors, either getting tenure or not getting tenure. If you get tenure you have job security for life, if you don't get tenure you have a bit of time, then you have to leave and find a new job. Or they ask people right before a presidential election, in the United States, between Mitt Romney and Barack Obama. How happy they would be if their person won and if their person lost. And it turns out for all of these, these events do have some influence on happiness. But it's not a large influence. And even the most influential, most powerful sorts of events like becoming paralyzed, make you miserable. For six months, for a year, and then you tend to get back to where you started from. Not perfectly, but we tend to get used to both positive and negative events. And there are couple of reasons why. One is that for some things we just fail to appreciate that certain things are irrelevant. So in the heat of an election campaign, when you ask somebody, how would you feel if your candidate loses? People might say, honestly, I'd feel miserable, I'm going to spend the next four years miserable. But the truth is, in day-to-day life, most of the time, you don't even think about who's president, it doesn't make any difference for you. And to a surprising extent, the things that you might think are incredibly important, like, I might win a tremendous prize and then think that'll make me very happy. For 99.99% of my life, the prize doesn't seem to make that much of a difference. I still have to deal with my family and take out the laundry and engage in my work. Day-to-day life is often simply uninfluenced by things at the time seem very important. And then the second reason why these events don't matter very much is the logic of the set point where you have a basic amount of how happy you'll be. And then when events happen, you adapt to them, and what this means is you simply get used to them. So you get used to certain bad things, your life is worse but you don't always feel it as worse. There's some surprising exceptions to this, happiness, researchers argue, you never really get used to a long commute. If you're miserable commuting to work on day one, you're going to be miserable a year later. And you don't adapt well to background noise, if there's loud noises that are distracting and annoying, you never fully get used to them. But for the most part, we adapt to bad things and we adapt to good things. So if I win a prize, if I get a great job, it's wonderful at the beginning and then you just get used to it. This is a variant of something we talked about early on in the course, habituation. There's some exceptions that some form of cosmetic surgery for instance, actually do make you happier. Maybe because how you see yourself and how others see you is something which is just long-lasting and pervasive in a surprising extent. Now, this is an old insight, there is a wonderful passage in the Bible in Ecclesiastes. Where a king had everything, gardens, parks, vineyards, castles, slaves, concubines. And then it goes on to say, I hated life, he says, all is vanity and a chasing after wind, and there is nothing to be gained under the Sun. Let's zoom in a little bit and ask about bad events, so how is it we adapt to bad events? A bad event like losing your job, losing a great sum of money, a breakup with somebody you love. All sorts of bad events, everything all the way up to becoming paralyzed. And there's different answers, so one answer I gave is that these bad events often don't affect as much of your life as you think they will. A second answer is, we simply get used to it, and that's adaptation. But a third answer is defended by Dan Gilbert, who talks about the psychological immune system. And the psychological immune system is a psychological mechanism that makes in a normal, a highly-functioning non-depressed person, makes you seek out the good side of things. Gilbert gives many examples of good people who, terrible things have happened. They've been falsely imprisoned and they look back and say, that was the best thing in my life. And this may be irrational but it seems to make us happier. And it seems to make us be able to better bounce back from bad events. There's a nice illustration of this in this very short, I think quite moving TED Talk. [MUSIC] >> [APPLAUSE] >> Imagine, if you will, a gift, I would like you to picture it in your mind, it's not too big, perhaps the size of a golf ball, some vision what it looks like, all wrapped up. Before I show you what's inside, I will tell you it's going to do incredible things for you. It will bring all of your family together, you will feel loved and appreciated like never before, and reconnect to friends and acquaintances you haven't heard from in years. Adoration and admiration will overwhelm you, it will recalibrate what is most important in your life. It will redefine your sense of spirituality and faith. You'll have a new understanding and trust in your body. You'll have unsurpassed vitality and energy. You'll expand your vocabulary, meet new people, and you'll have a healthier lifestyle. And get this, you'll have an eight-week vacation of doing absolutely nothing. You'll eat countless gourmet meals, flowers will arrive by the truckload. People will say to you, you look great, have you had any work done? >> [LAUGH] >> And you'll have a lifetime supply of good drugs. You'll be challenged, inspired, motivated, and humbled. Your life will have new meaning. Peace, health, serenity, happiness, nirvana. The price, $55,000, and that's an incredible deal. By now, I know you're dying to know what it is and where you can get one. Does Amazon carry it? Does it have the Apple logo on it? Is there a waiting list? Not likely. This gift came to me about five months ago, it looked more like this when it was all wrapped up, not quite so pretty, and this, and then this. It was a rare gem, a brain tumor, hemangioblastoma, the gift that keeps on giving. And while I'm okay now, I wouldn't wish this gift for you, I'm not sure you'd want it, but I wouldn't change my experience. It profoundly altered in my life in ways I didn't expect, in all the ways I just shared with you. So the next time you're faced with something that's unexpected, unwanted, and uncertain, consider that it just may be a gift. >> [APPLAUSE] [MUSIC] >> Now, I think a lot of what psychologists have learned about happiness, in particular what I've talked about in this section, corresponds well to ancient wisdom. And the wisdom is, it's not so much what happens to you that determines how happy you are, it's how you perceive it. And so I'll end with two quotes, one is by John Milton, and he attributes this to Satan and Paradise Lost. The mind is its own place and in itself, can make a heaven of hell, a hell of heaven. And finally Shakespeare, for there's nothing either good or bad but thinking makes it so.