April 14, 2008 -- Does higher testosterone in the morning lead to higher earnings for the day? According to new research, maybe so, if you are a stockbroker.
Researchers from the University of Cambridge went to the trading floor of a mid-sized financial firm in London to track 17 brokers on the job for eight days.
The aim was to measure both their testosterone and cortisol levels twice a day. All the brokers were men, all were healthy, and all reported not taking any drugs. They also were interviewed each day to make sure they did not receive any outside news that may have affected their hormone levels. Testosterone and cortisol are hormones that work to regulate metabolism and determine mood.
- Daily testosterone was significantly higher on days when traders made more than their one-month average.
- On days when the morning testosterone was higher, traders made a "significantly greater" profit.
- Study authors write that the findings suggest "high morning testosterone predicts greater profitability for the rest of the day."
Testosterone is associated with winning and risk taking.
Study authors John M. Coates and Joe Herbert speculate that if testosterone continues to climb or stays persistently elevated, it could begin to have the opposite effect, for instance creating harmful risk taking, being overly impulsive, or seeking out unhealthy thrills.
The study results appear in the Proceedings of the National Academy of Sciences.
Researchers were surprised by what they found with the traders' cortisol levels. They wanted to see if cortisol levels rose during a stressful day of losses. Cortisol is known as one of the "fight or flight" hormones related to the body's response to stress.
Cortisol levels did not change wildly due to big losses but seemed more connected to the unknown, whether the trader was uncertain about whether he would lose or make money.
Both cortisol and testosterone have receptors in the brain. Researchers believe that as these hormones fluctuate, they may disrupt a trader's decision-making ability.