I get a little pain in my knee when I walk down stairs or run long distances. The problem has gotten worse with age but has an easy fix — a short series of strength exercises. If I do them a few times per week, I’m pain-free.
The routine takes only about 15 minutes, and I can do it at home. Even so, I just can’t seem to make it a habit. I tell myself I’ll do it at the end of my workday, but when 5:30 p.m. rolls around, I often find myself unwinding with a run or a beer instead. “I’ll do the damn exercises tomorrow,” I promise myself. But the pattern repeats itself the next day, and often the next, sometimes until my knee starts hurting again.
Greek philosophers have a word for this behavior: akrasia, the state of acting against one’s better judgment.
While akrasia is sometimes called “weakness of will,” recent research suggests that it’s not a personal failing, but a result of a cognitive bias that strike us all — “time inconsistency,” our tendency to discount the future in favor of the present.
George Ainslie, a psychiatrist at the Veterans Affairs Medical Center in Coatesville, Penn., and behavioral economist at the University of Cape Town in South Africa, has spent decades studying akrasia. He’s found that if you give people a choice between a smaller, more expedient reward and a larger delayed one, timing has an interesting impact on their decisions.
“If you pretend it’s a game show and you offer people $50 today or $100 in two years, when you ask how many people would prefer $50 today, a lot of people raise their hands,” Ainslie says.
But if people can choose between receiving $50 in six years or $100 in eight years, nobody wants the $50, he says, even though it’s the same choice, just spread over a different time period. Such results show that people discount the future in an inconsistent way that gives preference to smaller, more immediate rewards, Ainslie says.
I choose happy hour over my knee-strengthening exercises because the pleasure of beer is immediate, while the pain I’ll prevent with my gym routine isn’t.
Battle of the Selves
“We all do it; it’s part of our nature,” says Piers Steel, a psychologist at the University of Calgary and a leading researcher on one of akrasia’s most common manifestations: procrastination.
Long-term planning, such as saving for retirement or committing to an exercise plan, is done in the brain’s prefrontal cortex. “Then we have the limbic system,” Steel says, “which is much more compulsive and focused on the here and now.” One way to see it, he says, is to think of our brain as a house with two floors, each with a different set of residents. The limbic system is the young, hip couple on the ground floor who are “energetic and passionate, and focused on the present,” he says. Meanwhile, the prefrontal cortex is the older couple upstairs who pay the mortgage and keep the house in order.