How We Decide

by Jonah Lehrer, 2009

Anecdotes

• Quarterback Tom Brady helped win the 2002 Super Bowl for the New England Patriots by making quick, accurate passing decisions.
• Lieutenant Commander Michael Riley was monitoring radar aboard a British destroyer off the coast of Kuwait during the Desert Storm invasion. He saw a blip moving toward the battleship USS Missouri. His instincts told him that the blip was dangerous; he ordered the launch of missiles that destroyed it. The blip could have been an American A-6 fighter, but turned out to be a Silkworm missile. He couldn't justify his decision. Later investigation showed that the pattern of the blip was a little different from that of an A-6 fighter.
• In the 1990's at IBM, Gerald Tesauro developed a backgammon-playing program called TD-Gammon that mimics human learning by learning from its mistakes.
• In a famous study, Carol Dweck had teachers administer a simple nonverbal test to fifth-graders. After the test, half the students were praised for their effort, the other half for their intelligence. On a subsequent test of equal difficulty, those who were praised for effort did much better than those who were praised for intelligence.
• Ann Klinestiver was diagnosed with Parkinson's, which kills off dopamine neurons. She was given a drug to stimulate dopamine production in the brain. She soon became addicted to gambling. The surprising rewards of the casino triggers a massive release of chemical bliss.
• A veteran smoke jumper named Wag Dodge was airlifted with his team into a dry, hot grassland that was on fire. They became trapped in Mann Gulch with a wall of flame rapidly approaching. Most of the team tried to run up the side of the gulch, but Wag used his noggin and lit his own escape fire in the grass. The grass quickly burned a circle around him. He burrowed into the embers as the wall of flame overtook him and his escaping men. He was the only survivor. He had invented the escape fire on the spot.
• Mary Jackson was a disciplined and successful pre-med in college. One summer, her behavior changed radically. She started experimenting with drugs and increasingly promiscuous sex. Her grades went from straight A's to F's. She was later diagnosed with a pituitary tumor that had derailed her prefrontal cortex. In one test, her doctor put a pen and paper in front of her and asked her to keep her hands still. She automatically started writing.

Neurology

• Patients without a functioning orbitofrontal cortex (OFC) do not experience emotion and cannot make complex decisions.
• The nucleus accumbens (NAcc) generates pleasurable feelings by releasing dopamine. Rats whose NAcc are electrically stimulated will lose interest in anything else and die of thirst.
• Dopamine is released in anticipation of a reward.
• An unpleasant surprise activates the anterior cingulate cortex (ACC), which helps us learn from mistakes.
• Dopamine neurons automatically detect subtle patterns and convey them to us through feelings.
• Lobotomized patients experience damage to the prefrontal cortex and suffer from deficits in short-term memory and impulse control.
• ADHD in children is highly correlated with retarded development of the prefrontal cortex. Symptoms are an inability to focus, sit still, or delay immediate gratification.
• The placebo effect is mediated by the prefrontal cortex, which routinely blocks input from other brain systems.

Conclusions

• We use our emotional brain to make quick judgments about complex situations.
• Intelligent intuition is the result of deliberate practice and analysis of one's mistakes.
• The emotional brain is good at finding patterns where there are none (slot machine, stock market, winning streaks), and can lead to bad choices.
• In human decision making, losses loom larger than gains.
• Buy now, pay later leads to poor choices.
• People who are more rational don't perceive emotion less, they just regulate it better.