Choking under pressure: Capuchin monkeys do it, too

In 1996, professional golfer Greg Norman entered the final round of the Masters Tournament with a six-stroke lead over the rest of the pack, giving him a clear advantage to win the green jacket. Norman said he arrived on the course that morning “totally in control.” His final score proved otherwise.

In what would go down as one of the most infamous performances in golf history, Norman proceeded to rack up seven bogeys and two double-bogeys (for the uninitiated, this is very bad), ultimately falling five strokes behind tournament winner Nick Faldo, who later told Golf Monthly: “I could feel the nervousness emanating from Greg. He gripped and regripped the club, as though he could not steel himself to hit the ball.”

Choking under pressure is a near-universal human experience. Although it doesn’t happen to everyone, and might only happen in certain circumstances (Norman won two major championships in his career, to be sure), it’s easy to see how our physiological responses to high-stakes situations can trip us up — even if we’re highly skilled at the task at hand.

But is choking under pressure unique to humans, or are its biological drivers more deeply rooted throughout the animal kingdom? That was the main question behind a study recently published in the journal Scientific Reports. Using capuchin monkeys as test subjects, the study found that humans aren’t the only primates vulnerable to choking in high-pressure situations and that the hormone cortisol seems to play a role in the phenomenon.

Capuchins and choking under pressure

In the study, researchers trained 20 capuchins to play a computer game in which a monkey was shown an image on the screen for two seconds before disappearing. The capuchin was then shown four images, one being the image that had recently disappeared. The monkey had to move a joystick to select that image. If correct, the monkey received banana-flavored treats.

But there was a catch: Some trials were more difficult but more rewarding. The researchers trained the monkeys to differentiate between these trials and the easier, less rewarding ones by changing the color of the computer screen. A blue screen represented a high-stakes situation.

To test whether monkeys choke under pressure, the researchers compared their performance across different levels of difficulty and reward. The researchers also measured the monkeys for levels of cortisol, which is a steroid hormone that is naturally produced in humans and other animals. Cortisol plays a key role in the stress response, serving as something like the body’s natural alarm system.

Cortisol also seems to be involved in choking under pressure; in human studies, choking is associated with higher cortisol levels. (Somewhat counterintuitively, research has found that people with greater working memory — that is, one’s ability to temporarily retain information relevant to the task at hand — seem to be more vulnerable to choking in stressful situations where cortisol levels are higher.)

The results of the experiments showed that some monkeys seem to choke under pressure. Cortisol levels in the monkeys were significantly negatively related to performance within the high-pressure trials but less so in the low-pressure situations. But not all monkeys were vulnerable to choking; the results revealed significant differences between individuals, which aligns with prior human studies showing that some people actually thrive under pressure while others choke.

Adapting to pressure

It’s worth noting that all of the monkeys — even the chokers — did get better at the task over time.

“Our data support a model of individual differences in choking under pressure in which an individual’s long-term cortisol level is negatively correlated with performance under pressure in early attempts to perform, but experience with performing under pressure mitigates these negative effects,” the researchers noted.

Although the results don’t establish a causal link between choking and cortisol, the researchers suggested that “ongoing exposure to stress is related to the ability of an individual to cope with an acutely stressful situation and, therefore, the individual differences we see in choking.” Supporting that idea is prior research showing that animals that have been subjected to chronic stress display suppressed cortisol levels during acutely stressful situations.

So, what does this mean for people choking under pressure? The results suggest that choking is an evolved phenomenon with deep roots extending to other animals (capuchin monkeys, at least) and that cortisol seems to be a key factor in the process. Another part of the process, which could potentially be related to cortisol levels, is overthinking.

A 2021 study used functional near-infrared spectroscopy (fNRIS) to image the brains of soccer players as they attempted penalty kicks. The results showed that experienced soccer players who missed shots showed high activity in the left temporal cortex, which is related to self-instruction and self-reflection, while they showed lower activity in brain regions associated with automatic skills.

“By activating the left temporal cortex more, experienced players neglect their automated skills and start to overthink the situation,” the researchers wrote. “This increase can be seen as a distracting factor.”

Still, how exactly cortisol might interact with overthinking, if at all, is a question for future research.