How We Decide

October 6, 2010

The brain is an argument.

One of the most interesting revelations in the book is how the brain is essentially an argument. Every decision pits parts of our brain against each other, and the one that wins out is the decision we make. Putting shoppers in an MRI machine, we see that when exposed to desirable products, the nucleus accumbens (NAcc) floods the brain with dopamine, making us feel good and wanting to reward ourselves. But when exposed to the price of a product, the insula lights up, which is the part of the brain that triggers aversive feelings, such as when we see people in pain. Shopping is thus like a tug-of-war between the NAcc and the insula, with shopkeepers making every effort to aid the NAcc by making us feel good about spending (such as with meaningless but effective stickers that say “Hot Buy!” or “Low price!”). It’s also useful to put the most desirable objects right by the door: even if someone isn’t shopping for a TV, the sight of a 56” big-screen when they walk in gets the NAcc excited and actually increases the chances that the person will splurge on a more expensive cereal. Certainly, a more sexualized shopping experience would have a similar effect. Show pictures of attractive people to prime the NAcc, and maybe people will spend more on christmas presents. One might call this the Hollister/Abercrombie effect.

We often think we’re rational shoppers, but almost all purchase decisions are “outsourced” to the emotional parts of the brain. We don’t have time to research and carefully consider every option and relevant factor when shopping for everyday things, so we often go with whichever product “feels” right. This is why marketing people have jobs.

Overall, however, some decisions are better left to the emotional rather than the rational brain. Researchers did an experiment: there are two decks of cards which all indicate plus or minus some amount of money. One deck has more good cards than bad. When asked to pick from the two decks, people start off randomly and by about the 20th pick they start to get a sense of which deck has more good than bad cards. But at around the 10th card, our palms start to get sweaty when we’re picking from the “bad” deck, meaning our emotional brain knows which deck is which long before our conscious brain does!

Guidelines for Making Better Decisions

Simple problems require reason
A simple problem is one in which relatively few details matter, like buying a cheese grater. Assuming all cheese graters grate cheese, the only relevant detail is the price. Your emotions may be misled by the sexy fire-engine red color or the story on the box of the lonely artisan working late into the night to hone the perfect cheese grater, but use your reason to penetrate to what really matters.
Novel problems require reason
If you’ve never been in a situation before, your emotions can lead you astray. If you wake up tied up in a basement, your instincts will tell you to panic uselessly. Only reasoning about your situation will save you.
Constantly remind yourself of what you don’t know
That way, when you can get that information you’ll be ready for it and know you need it. Colin Powell gave this mandate to his intelligence analysts: “Tell me what you know, then tell me what you don’t know. Only then can you tell me what you think.”
You know more than you know.
Your sweaty palms know which deck is stacked twice as soon as your brain figures it out. For complex situations when you don’t or can’t consciously entertain all the relevant info, don’t be afraid to rely on your gut. And when you do, keep your brain from second-guessing. Your brain unconsciously tallies every failure and learns from it, even when you fail it makes you a better decision-maker.

Also interesting

Gambling as counterfeit learning: As far as dopamine is concerned, surprise rewards are 3-4 times more exciting than predictable ones. This is why gambling is so enticing. The brain kicks into “happy fun learning mode” trying to figure out how to predictably repeat this windfall, though this is of course impossible in the case of random chance. But the joy a gambler feels is the same as the joy felt by a scientist–it’s a joy of learning as the brain tries to figure out a pattern–except that in the case of the gambler there is no pattern.

You could be a pedophile: neurological problems can cause gambling and drug addictions and pedophilia (p. 105). Each of us is just one stroke, hemorrhage, or knock on the head away from being a rampant pedophile, psychotic or addict, so let’s consider this when forming opinions about how our society should treat such people.