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Dead Kennedys, Testosterone-Crazed Skateboarders, and You

The Evolutionary Psychology of Risk

You might not think that observing testosterone crazed skateboarders could inform us about the fundamental bases of economic decision-making, but they can. To see why, let’s begin by considering one the most successful men in American history.

At age 25, Joseph Patrick Kennedy became America’s youngest bank president. At the time, he bragged to a newspaper reporter: “I want to be a millionaire by the age of thirty-five” (quite an aspiration in 1915, when average income was $1,076, and a loaf of bread cost 9¢). Kennedy made good on his lofty aspirations, though, becoming a Wall Street trader, and turning a profit of $650,000 on a single transaction in 1922. Kennedy shrewdly arranged to import liquor just as Prohibition was lifted, and he sold off his stocks just before the stock market took its infamous nosedive. He moved out to Hollywood and helped found RKO pictures (with assets of over $80 million).

Joseph Patrick Kennedy

Kennedy was a shining example of the rational self-interest at work, not only in his financial dealings, but also in his personal life: After having an affair with the beautiful movie star Gloria Swanson, for instance, he left her holding the tab when her movie went grossly over budget. Later in life, he turned his ambitions from finance to political power. He became the American ambassador to England, and plotted to have his oldest son become president of the United States.

On the classic view of decision-making -- the view that dominated the field of economics for well over a century -- we are all like Joe Kennedy: highly rational beings who are surprisingly good at knowing which choices will favor our self-interest. As Joseph Kennedy did when he decided to sell his stock holdings or to end his relationship with Gloria Swanson, we all make choices based on the best available information about what we expect will maximize our future satisfaction.

Rational Econs versus Irrational Morons

During the last decades of the twentieth century, behavioral economists raised a radical challenge to the classic economist’s assumptions that human decisions are fundamentally rational and well-informed. On the behavioral economic view, everyday people’s judgments are often simple-minded, irrational, and self-defeating. The behavioral economists have not only disagreed with view of humans as ultra-rational “Econs,” they have in fact conducted hundreds of experiments demonstrating various irrational biases in human decision-making.

Joe Kennedy’s descendants seem like poster children for this later view -- of people as irrational decision-makers. Joe’s handsome and charming eldest son, Joseph Jr. -- the one he hoped would someday become president – had flown enough bombing missions during World War II to qualify for a discharge. But just before he was supposed to board a flight home, he rashly volunteered to fly a plane full of explosives straight at a heavily fortified German encampment. The outcome was a funeral instead of a successful political career. Joe’s second-born son, John, did get elected to the U.S. presidency. But John made a number of notably rash decisions, such as using Secret Service agents to be on the lookout for his wife when he snuck beautiful women into the White House for trysts. To make bad judgment worse, one of JFK’s mistresses was, as Republicans later leaked to the press, a friend of Mafia don Sam Giancana. Then Joe’s youngest son Edward, after a night of drinking too much, drove his car off a bridge on Chappaquiddick Island, in an infamous accident that drowned his passenger, Mary Jo Kopechne (Teddy was married at the time). Joe’s grandchildren seemed even more handicapped by irrational judgements – one grandson died of drug overdose in a Miami hotel, and another died playing football whilst zooming down a tree-filled mountain slope on a pair of skis. A third, JFK’s strikingly handsome son John Jr., seemed to be doing well in life, until he decided to fly his personal plane into the fog one night, and ended up at the bottom of the ocean.

Deep Rationality and Testosterone-Crazed Skateboarders

Are we ultra-rational Joe Kennedys, as the classical economists claim? Or are we, like some of his descendants, bumbling and careless decision-makers, as the behavioral economists argue? Or is possible that neither of these views is completely correct. On an emerging evolutionary view of decision-making, the choices made by you, me, and the Kennedys, are educated by the wisdom of underlying principles developed over millennia, during which our ancestors successfully solved the problems of existence and exchange in human groups. Yes, decision-making is biased, and yes, individual decisions are sometimes rather moronic, but looked at in another way, we are rational in ways that even the classical economists could not have dreamed.

Let’s reconsider the risky decisions made by the Kennedy clan in light of this perspective. On an evolutionary perspective, any decision, whether it involves an obviously risky or a seemingly safe venture, involves trade-offs. A risky choice can be dangerous or costly, but it could also lead to huge payoffs in terms of money, status, and access to reproductive opportunities. However, these payoffs don’t come from taking risks blindly. Instead, most of our ancestors would have turned their risk-seeking appetites on or off depending on where they were, and who was watching.

To begin to understand how this works, consider a clever field study by two psychologists at a skateboard park in Queensland, Australia. Richard Ronay and William von Hippel offered 96 young skaterboarders $20 to perform two tricks. The researchers asked the skateboarders to choose one easy trick and one they found more difficult (a stunt they were working on, but could only complete successfully about half the time). At the beginning of the study, a male experimenter filmed the skateboarders as they practiced their two tricks several times. Midway through the filming, though, a highly attractive 18-year-old female arrived on the scene. To verify that guys found her quite good-looking, the researchers asked 20 other guys to rate her attractiveness. Not only did she score as a knock-out on the scale ratings, but the ratings were, as the researchers noted, “corroborated by many informal comments and phone number requests from the skateboarders.” After demonstrating his tricks a few more times, each skateboarder donated a sample of saliva to the researchers, who later had it analyzed for testosterone levels.

When the beautiful woman was watching, the skaters took a lot more chances. As a result, two things happened: on the negative side, they had a lot more crash-landings, but on the positive side, they were more likely to succeed on the difficult tricks. As the experimenters concluded: “beautiful women lead men to throw caution to the wind.” This boost in riskiness was linked to several other interesting findings. First of all, men’s testosterone levels went up when there was a beautiful woman watching. In fact, the boost in riskiness was found primarily among those men whose testosterone levels zoomed up the most. Finally, the researchers gave the men a test that taps into functioning of the brain’s ventral medial prefrontal cortex (an area involved in careful assessment of rewards and punishments). When there was a beautiful woman watching, men did worse on the test, suggesting that perhaps this area of the brain -- normally involved in making careful judgments -- was turned off by the boosts in testosterone. The researchers suggested that these findings make evolutionary sense to the extent that successfully showing off to a beautiful woman would have been more likely to enhance a man’s chances of attracting her as a mate. To show off, though, a bloke needs to be willing to turn off the brain’s caution mechanisms, and take some otherwise foolish risks.

As part of an electronic textbook project, we brought Prof. Von Hippel to a local skateboard park to talk about this fascinating research. You can check a short animated video here.

Meanwhile, back in Hyannis Port

A closer look at the Kennedy clan suggests that their judgments weren’t, on average, quite so irrational after all. Despite all the tragedies that transpired during the 55 years between the plane crashes that took the lives of Joe Jr. and John Jr., the Kennedy clan had more than the average share of good luck, more than the average share of financial and social success, and most importantly, more than the average share of surviving offspring. Indeed, the still-living descendants of Joseph Kennedy are abundant in number, rich in resources, and blessed with social status, connections in the highest of places, and plenty of good judgment. Despite the Chappaquiddick incident, Ted Kennedy went on to become the fourth longest serving Senator in U.S. history, and a powerful force on the world political stage until his death at age 77. Joseph’s surviving grandchildren include U.S. representatives, lieutenant governors, highly successful businessmen, film producers, and philanthropists. And those grandchildren have themselves produced over 60 great grandchildren, who are similarly blessed with abundant wealth, opportunity, and social connections to other rich and powerful people. So, despite the occasional bad judgments, the Kennedys seem to have made plenty of good decisions as well.

From an evolutionary perspective, the Kennedys were successful not in spite of their nature, but because of their nature. The Kennedys may not be Econs, but neither are they Morons. They are Humans, and their judgments were more often wise than foolish. Likewise for the rest of us – although some of our particular decisions are annoyingly ill-informed, we manage to get by reasonably well, on average. Similarly for our sometimes feckless parents, and for their uneducated and uncouth predecessors, who all made judgments that were, at the very least, good enough that we are now here to talk about it.

Yes, decision-making is biased, and yes, individual decisions are sometimes rather moronic. But underneath all those biases and misjudgments is a system characterized by what my colleagues and I call Deep Rationality. On this view, the decisions made by you, me, the Kennedys, and those testosterone-crazed skateboarders in the land down under, are all educated by the wisdom of underlying principles developed over millennia, during which our ancestors successfully solved the problems of existence and exchange in human groups.

This post is based on material originally presented in my book with Vlad Griskevicius: The Rational Animal: How evolution made us smarter than we think. We go into more detail on the differences between the rational man perspective, the behavioral economic perspective, and the evolutionary perspective on decision-making in that book.

Related blogs

The evolved wisdom behind our seemingly stupid decisions. Are you smarter than you think?

How a passing mood can alter your economic decisions. Can mating motives alter classic loss aversion?

Deep rationality: Evolutionary psychology meets behavioral economics.


Kenrick, D.T., & Griskevicius, V. (2013). The rational animal: How evolution made us smarter than we think. New York: Basic Books

Ronay, R., and W. von Hippel. (2010). “The Presence of an Attractive Woman Elevates Testosterone and Physical Risk Taking in Young Men.” Social Psychological and Personality Science 1: 57–64.