20만년전 인류는  빙하기의 혹독한 가뭄 앞에서 멸종위기에 처했다. 풍요한 아프리카 조차 사막으로 뒤덥혔다. 먹을 것은 커녕 마실 물조차 제대로 구하기 힘들었다. (빙하기엔 지구상의 수분이 얼음으로 바뀌기 때문에 기후가 대단히 건조해진다.)

호모 사피엔스는 그런 악조건을 "상상력"으로 극복해 냈다. 물이 언제 필요할지, 어떻게 구할수 있을지 예측하고 준비함으로써 혹독한 빙하기를 이겨냈다. 그러면서 발달한 두뇌가 전전두엽이다. 우리는 전전두엽을 이용해 계획도 하고, 예측도 하고, 미래의 상황에 대한 시뮬레이션도 한다.

그런데, 바로 그 "상상력"때문에 인간은 행복하기도 하고, 불행하기도 한다. 한가지 사실에 너무 집착해, 그 한가지 사실을 부풀려 미래를 시뮬레이션 할때 불행이 싹튼다. 대안이 있는 것처럼 보일때, 처한 현실을 비관하고, 피하려고 한다.

그러나, 사람에겐 심리적 면역체계가 있다. 어떠한 곤경에 처해도 우리가 낙관할 수 있는 무의식작용이다. 현실상황에 대한 선택의 여지가 없을 때 심리적 면역체계가 더 잘 작동한다. (사실 호모 사피엔스는 그렇게 진화했고, 이 시스템 덕에 날카로운 이빨, 두터운 가죽, 강인한 팔다리가 없이도 번영할 수 있었다.)  

행복은 내가 갖고 있는 것을 긍정하는 낙관에서 온다. 그 낙관은 우리의 심리적 면역체제가 만들어 내는 "인조"행복이다. 인간은 바로 그 인조행복감을 통해 불행한 사건을 행복한 현실과 미래로 일궈낸다.

어떤 비극적 현실에 얽매여 선택의 여지가 없을 때라도, 바로 그 부정적 현실이라는 돌부리에 걸려 비틀거릴때, 그 돌부리는 피할 수 없는 우리의 현실이다. 우리를 비틀거리게 하는 현실이다. 비틀거리면서 "희망"이라는 심리적 면역체계가 작동한다. 그 돌부리가 행복으로 바뀌는 순간이다.    

"행복에 걸려 비틀거리다"의 저자 다니엘 길버트의 TED 강연.

영문 대본 일부

00:24 When we have 21 minutes' speak, two million years seems like a really long time, but evoluationary two million years are nothing.

00:34 Yet in two million years human brain has nearly trippled in mass.

00:38 Going from one and quarter pound brain of our ancestor here Habilis to the almost three pound meat loaf that everybody has between their ears.

00:48 What is it about a big brain that nature was so eager for everone of us wanted to have one.

00:54  Well it turns out when brain tripples in size, they just don't get three times bigger. They gain new structures.

01:00 And one of the main reasons that our brains got so big is because it got a new part called the frontal lobe, particularly a part called the prefrontal cortex.

01:10 Now what is prefrontal cortex do for you that should justfiy the entire architecural overhaul of the human skull in the blink of evolutionary time?
 
01:12 What is prefrontal cortext do for you that you justify architecture of overall human skull in the blink of evolutionary time . 

01:22 Turns out prefrontal cortex does lots of things. One of the most important things it does is experience simulator.

01:35 Human being have this marvelous adapation. They can actually have their experiences in their heads before they try them out in real life. This isn't treatment. None of our ancestors could do, none other animals can do quite like we can.  

01:50 It is a marvelous adaptation. It's up there with _____ thumbs, standing upright with language, as one of things that got our species out of trees into the shopping mall. ^^

2:00 Now, all of you havn't done this. Ben and Jerry dosn't have libera___ onion icecream. It is not because it whip some up try and didn't yuck. It's because from ,without leaving an armchair, we can simulate that flabor and say yuck before make it.

2:20 Let's see how your experience-simulators are working. Just want a quick diagnostic before I proceed the rest of the talk.

2:27 Here is the two different futures that I invite you to contemplate and you can try to simulate them and tell me which one you might be prefer.
 
02:37 One of them is winning the lottery. This is about 314 milion dollars and the other is becoming paraplegiacs.

2:43 So just give it a moment of thought. You probably feel like don't need a moment of thought.

2:51 And interestingly, there are data on these of two groups of people, data on how happy they are.  

2:55 And this is exactly what you expected, isn't it? But these aren't the data. I made it. These are the data. You failed the pop quiz in hardly 5 miniutes lecture.

03:07 The fact is, the year after they losing the legs, and the year after winning the lotto, lottery winners and paraplegic are equally happy with their lives.

04:30 Happiness can be synthesized.
04:32 "I am the happines man alive. I have that in me that can convert poverty to riches, adversity to prosperity, and I am more invulnerable than Achilles; fortune hath not one place to hi me." by Thomas Browne from Religio Medici (1642)

04:55 Human beings have .... psychological immune system, a system of cogntive processes largely non-conscious cognitive processes that help them change their views of the world so they can feel better about the world in which they find themselves.
05:10 People synthesize happiness, but we think happiness is to be found.

15:15 Psychological immune system works best when you are stuck, trapped.
 
19:43
Turgid Truth by Adam Smith, from "The Theory of Moral Sentiments, 1759
"The great source of both the misery and disorders of human life, seems to arise from over-rating the difference between one permanent situation and another ... Some of those situation may, no doubt, deserve to be preferred to others; but none of them can deserve to be pursued with that passionate ardour which drives us to violate the rules either of prudence or of justice; or to corrupt the future tranquility of our minds, either by shame from the remembrance of our own folly, or by remorse from the horror of our own injustice."

20:20 In other words, somethings are better than other. We should have preferences lead to future over another. When those preferences drives us too hard or too fast, because we overrated the difference between these futures, we are at risk.
20:42 When our ambition is bounded, it leads us joyfully. when our ambition is unbounded, it leads us to lie, to cheat, to steal, to hurt others, to sacrifice things from real value.
20:53 When our feels are bounded, we are prudent, we are cautious, we are thoughtful. When our feels are unbounded and overblown, we are reckless and we are cowardly.
 
21:06 The lesson I want to leave with you from these data is that our longings and worries are both to some degree overblown because we have in us to capacity to manufacture the very commodity we are constantly chasing when we choose experience.

이누이트님은 이 책을 읽어도 행복해지는 방법 모른다고 하셨는데, 실은 이누이트님도 "행복에 걸려..."에서 말한 행복해지는 법(포스팅의 서두와 말미의 결혼이야기)을 말하셨습니다. 결혼이야기를 좀더 확대해석하자면, 결혼은 해도 행복, 안해도 행복이라고 봅니다. 결혼을 하지 않는 것도, 일종의 "해버린"것이 되니까요. 결혼을 안해버리면, 싱글이기에 삶이 편하면 후회할 일 없고, 좀 외로워도 뇌가 합리화해 줄테니까요. "가지 않은 길"을 아쉬워하지만 않으면, 어떤 일을 당해도 행복하게 살수 있다는 것이지요.