Throughout the day we make an infinite number of decisions, many of which involve some type of risk. However, we do not approach potential gains and losses in the same way.
When it comes to winnings, we are more likely to choose a 100% chance of getting a small reward over a lower chance of getting a bigger one. However, with losses the picture changes: if the alternative is a small loss, we are more inclined to bet and risk losing even more.
Obviously, we don’t all approach rewards and losses in the same way, but in general our preferences for the level of risk we’re willing to take depend largely on dopamine and serotonin, two neurotransmitters whose levels vary over time throughout the day.
How does our ability to take risks vary?
Neuroscientists from University College London analyzed 26,720 people who took part in an exercise in which they had to make risky decisions. Each participant started with 500 points and made 30 attempts.
In each trial, they could choose between the “safe” option (a known and guaranteed point change) or the “risky” option (giving them a 50/50 chance of two possible outcomes).
The researchers designed three types of tests. In “win tests”, the safe option was a specific point increase, while gambling might give them more points or none at all. In the “loss tests”, the safe choice was a specific point loss while betting led to more point loss or no points being subtracted. In the mixed tests, the choice was between no change in points or a bet with a potential loss and a potential win.
After analyzing the first results, the researchers discovered that the time of the day did not influence the decisions of the participants in the mixed or gain tests. However, the same did not occur in the risk tests. In that case, most people, regardless of age or gender, chose the riskier options that could lead to bigger losses later in the day.
Why are we more prone to taking risks as the day progresses?
The researchers hypothesize that this greater propensity for risk may be due to a gradual loss of sensitivity to the increase in losses, which would become more evident as the day progresses.
The fact that we are more willing to take risks at night is partly related to the variation in serotonin and dopamine levels. Dopamine levels, for example, drop throughout the day. Serotonin levels also vary, decreasing as night falls.
Dopamine acts as a learning cue that shapes our behavior to maximize rewards and avoid punishment. It has also been found that the reduction of serotonin levels increases the subjective value of risky options. Therefore, it is likely that these normal changes in our brain chemistry lead us to take more risks at night, risks that during the day we would not be willing to take.
This discovery helps us to better understand how our brain works, so that if we have to make important decisions, it is better that we do it in the morning, when we can think more clearly to weigh the pros and cons, instead of jumping directly to choose the riskiest option.
Bedder, R. L. et. Al. (2023) Risk taking for potential losses but not gains increases with time of day. Scientific Reports; 13: 5534.
Clark, C. A. & Dagher, A. (2014) The role of dopamine in risk taking: a specific look at Parkinson’s disease and gambling. Front Behav Neurosci; 8: 196.
Long, A. B. et. Al. (2009) Serotonin shapes risky decision making in monkeys. Soc Cogn Affect Neurosci; 4(4): 346–356.