When faced with making a complicated decision, our automatic instinct is to limit — or prune — choices that might have a negative consequence. But this often leads to missing out on greater rewards. According to new research, it may even contribute to depression.
The results of a new study from researchers at University College London suggest that our brains subconsciously filter out options when faced with a complex decision. For instance, when faced with making a series of decisions, where each step depends on the previous one, we often feel overwhelmed.
This leads to simplifying the problem by avoiding any plan where the first step has a seriously negative association — no matter what the overall outcome would be. This “pruning” decision-making bias can result in poor decisions, according to the researchers.
Lead author Quentin Huys, Ph.D., from the UCL Gatsby Computational Neuroscience Unit explained: “Imagine planning a holiday. You could not possibly consider every destination in the world. To reduce the number of options, you might instinctively avoid considering going to any countries that are more than five hours away by plane because you don’t enjoy flying.
“This strategy simplifies the planning process and guarantees that you won’t have to endure an uncomfortable long-haul flight. However, it also means that you might miss out on an amazing trip to an exotic destination.”
During the study, the researchers asked a group of 46 volunteers with no known psychiatric disorders to plan chains of decisions in which they moved around a maze. On each step they either gained or lost money. The volunteers instinctively avoided paths with large losses, even if those decisions would have won them the most money overall.
Surprisingly, the amount of pruning the volunteers showed was related to the extent to which they reported experiencing depressive symptoms, though none were actually clinically depressed, the researchers note.
The researchers link the association with depressive symptoms to the brain chemical serotonin, which is known to be involved in both avoidance and depression. However, the researchers said this needs further study.
Source: University College London