Alex Tabarrok has a new paper out showing that easy availability of guns increases the number of suicides. (Read the comments section on that post, it’s full of good tidbits like the fact that there are more suicides farther from the equator.) This is an econometric study, but there is a psychological angle:

Our econometric results are consistent with the literature on suicide which finds that suicide is often a rash and impulsive decision–most people who try but fail to commit suicide do not recommit at a later date–as a result, small increases in the cost of suicide can dissuade people long enough so that they never do commit suicide.

In other words, while we think of some people as “suicidal” this is just the fundamental attribution error rearing its ugly head. Another example:

  • That other person didn’t signal before changing lanes because they’re a bad driver.
  • I didn’t signal before changing lanes because I forgot, I’m tired, my kids are yelling in the backseat, etc.

People’s behavior is determined by the situation, their feelings are transient or generated on the spot. Very little of their behavior can be pinned to permanent characteristics or explicit intentions. But our first inclination is the opposite. If this  idea tickles your fancy — if you’d like to learn a lot more about how the situation can affect your behavior — read The Person and the Situation, even though it didn’t make my list of top 5 behavioral economics books and even though Malcolm Gladwell wrote the Introduction. You should also browse this deck of cards showing how the physical design of the environment can affect your actions.

There are also fascinating implications for the study of crime. Gary Becker revolutionized the field by pointing out that crime isn’t done by “criminals” — it’s done by ordinary humans who face different costs and benefits than the rest of us. Of course, this isn’t the final word. Most crimes are crimes of passion; between a fifth and a third of prisoners were drinking at the time of their offense. To prevent crime, we don’t need to make 25 year sentences longer, we need to somehow get around all that System 1 decision-making. And an important new paper shows that Cognitive Behavioral Therapy is staggeringly effective:

The intervention … included … in-school programming designed to reduce common judgment and decision-making problems related to automatic behavior and biased beliefs, or what psychologists call cognitive behavioral therapy (CBT). Program participation reduced violent-crime arrests during the program year by … 44 percent … the benefit-cost ratio may be as high as 30:1 from reductions in criminal activity alone.

The paper also finds improved schooling outcomes. Reducing the importance of your automatic decision-making can have huge benefits. The alternate strategy — what Tabarrok’s paper on suicide suggests — is that you should also lower the size of the mistake that your System 1 self can make. Your impulsive self can really screw you over if you’re not careful: make sure he doesn’t have a gun.