Learning From Mistakes

People with a genetic mutation that reduces the number of dopamine receptors in the ACC suffer from a similar problem; just like the monkeys, they are less likely to learn from negative reinforcement. This seemingly minor deficit has powerful consequences. For example, studies have found that people carrying this mutation are significantly more likely to become addicted to drugs and alcohol. Because they have difficulty learning from their mistakes, they make the same mistakes over and over. They can't adjust their behavior even when it proves self-destructive.

John Lehrer
How We Decide

Angry Smokers

People with anger issues may be more likely to get hooked on smoking cigarettes because they find it soothing. A brain imaging study out of the University of California discovered that nicotine can dull anger responses. Nonsmokers in the study who were more likely to retaliate when they took a placebo than when they were given half of a nicotine patch. Details are in the journal Behavioral and Brain Functions.