Car keys next to a tumbler of alcohol

The lure of alcohol's immediate rewards outweighs the possible future punishment of driving drunk. (Photo Credit: Shutterstock)

How evolution shaped our decision-making

Our brains evolved to value near-term rewards over long-term threats, and that wiring creates challenges for treating addiction.

Our brains evolved to make decisions that favor short-term gain. That's why we spend five dollars on a latte instead of tucking it away in our 401(k).

This preference for immediate satisfaction makes it challenging to develop policies that nudge addicts toward the straight and narrow. "An alcoholic person will always choose the swift and certain rewards of a drink now over the possible threat of punishment at some future time," said Keith Humphreys, professor of psychiatry and behavioral sciences.

In a recent Wall Street Journal essay, Humphreys highlighted the success of a policy called 24/7 Sobriety that allows people with multiple drunken driving arrests to keep their licenses, so long as they prove twice a day that they haven't been drinking. Punishment is mild – a night in jail – but swift and certain if they are caught with alcohol in their bloodstream. And, according to a 2013 study, repeat offenses were down 12 percent where that policy was in effect.

"Lots of law enforcement people read it but at the same time didn't completely buy it," Humphreys said. That policy doesn't make sense unless a person understands that our brains are wired to take the treat unless danger is imminent.

So when Humphreys was asked to speak about addiction policy to an assortment of law enforcement officers, attorneys and judges, he took an unusual approach and dived into the science.

"I started with evolutionary theory, the conservation of neuro-circuitry that helped us survive, and how we all carry with us a decisional system that values swift and certain rewards over distant and probabilistic threats," he said.

And the results surprised him.

"The rest of the conference everyone kept telling me that they had never thought about the neurological basis of why addicted offenders do what they do and why criminal justice systems which ignore this reality fail over and over again," he said.

In the past year Humphreys, Brian Knutson, associate professor of psychology and neuroscience, and Robert Malenka, a professor of psychiatry and behavioral sciences, launched the Stanford Neuroscience Institute's new NeuroChoice initiative, which intends to leverage what is being learned about the brain to improve addiction policy.

"This is an example of how basic neuroscience principles can have an impact," said Malenka, who is also the Nancy Friend Pritzker professor and a member of Stanford Bio-X. His work has focused on the intricate brain wiring that controls addiction.

A deeper understanding of our brains that were wired for leaner times is necessary for creating policies that are effective in today's world, Humphreys said.

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