The neuroscience of choice exposes the power of ideas
Have you ever watched a white rat choose between an 8 percent and a 32 percent sucrose solution by pressing two different bars on variable-interval schedules of reinforcement? No? Lucky you. I devoted two years of what would otherwise have been a misspent youth to running choice experiments with rats in Skinner boxes at California State University–Fullerton under the direction of Douglas J. Navarick for a master’s thesis in 1978, “Choice in Rats as a Function of Reinforcer Intensity and Quality.” Boys gone wild!
Since then, behaviorists’ black box has been penetrated by neuroscientists, most recently by Read Montague from the Institute of Advanced Study in Why Choose This Book? (Dutton, 2006). Montague argues that our brains evolved computational programs to evaluate choices in terms of their value and efficiency: “Those that accurately estimate the costs and the long-term benefits of choice will be more efficient than those that don’t—and in the long term these are the winners.”
Life, like the economy, is about the efficient allocation of limited resources that have alternative uses (to paraphrase the economist Thomas Sowell). It all boils down to energy efficiency. To a predator, says Montague, prey are batteries of energy. “This doctrine mandates that evolution discover efficient computational systems that know how to capture, process, store, and reuse energy efficiently.” Those that do, pass on their genetic programs for efficient computational neural processing to make efficient choices. Over the course of millions of years, says Montague, our brain has evolved to be so efficient that it consumes about a fifth of the energy of an average lightbulb, costing about a nickel a day to run.
Computational programs are designed by evolution to learn how to solve certain tasks. Rats, for example, inherit programs that are especially good at learning mazes and pressing bars because they evolved to forage in dark and spatially complex environments. There are no blank slates for mice or men. “Despite their differences,” Montague explains, “all goals have one thing in common: They can all be used by our brains to direct decisions that lead to the satisfaction of the goal.”
Unfortunately, these evolved computational programs can be hijacked. Addictive drugs, for example, rewire the brain’s dopamine system—normally used to reward choices that are good for the organism, such as food, family, and friends—to reward choosing the next high instead. Ideas do something similar, in that they take over the role of reward signals that feed into the dopamine neurons. This includes bad ideas, such as the Heaven’s Gate cult members who chose suicide to join the mother ship they believed was awaiting them near the comet Hale-Bopp. The brains of suicide bombers have been similarly commandeered by religious and political bad ideas.
In The Science of Good and Evil (Times Books, 2004) I argued that we evolved moral emotions that operate similar to other emotions, such as hunger and sexual appetite. Thinking of these emotions as proxies for highly efficient computational programs deepens our understanding of the process. When we need energy we do not compute the relative caloric values of our food choices; we just feel hungry for certain food types, eat them, and are rewarded with a sense of satisfaction. Likewise, in choosing a sexual partner, the brain employs a computational program to make you feel attracted to people with good genes, as indicated by such proxies as a symmetrical face and body, clear complexion, and a 0.7 waist-to-hip ratio in women and an inverted pyramid build in men. Similarly, in making moral choices about whether to be altruistic or selfish, we feel guilt or pride for having done the wrong or the right thing, but the moral calculation of what is best for the individual and the social group was made by our Paleolithic ancestors. Emotions such as hunger, lust, and pride are stand-ins for these computations.
How can we utilize this theory of choice to our advantage? Montague employed fMRI brain scans to discover that certain brands, such as Coke, “change dopamine delivery to various brain regions through their effect on reward prediction circuitry.” The Coke brand has a “flavor” in the ventromedial prefrontal cortex, a region essential for decision making. Just as Coke is a proxy for flavor, hunger a proxy for caloric need, lust a proxy for reproductive necessity, and guilt and joy proxies for immoral and moral behavior, so too can we market moral brands to rewire brains to value and choose good ideas.
In honor of the late economist Milton Friedman, author of the radical book Free to Choose, I propose that we begin by marketing this brand—the Principle of Freedom: All people are free to think, believe, and act as they choose, as long as they do not infringe on the equal freedom of others.