Too many choices deplete mental acuity: U.S. researchers
Last Updated: Tuesday, April 15, 2008 | 12:31 PM ET
CBC News
People faced with many choices — over anything from consumer products to college courses — find it difficult to stay focused enough to complete projects and handle daily tasks, say U.S. researchers.
While having choices is often thought of as a good thing, research led by the University of Minnesota's marketing department found we are more fatigued and less productive when faced with a lot of choices.
Researchers from several U.S. universities conducted laboratory experiments with undergraduate students and their findings appear in the April issue of the Journal of Personality and Social Psychology.
Participants were randomly assigned to make choices about consumer products, college courses or class materials. Other participants were not asked to make decisions but simply to consider options.
Each group was then instructed to participate in one of two unpleasant tasks. Some were told to finish a healthy but ill-tasting drink — akin to taking one's medicine and a measurement of self-control. Other participants were told to put their hands in ice water for as long as possible, also as a way of measuring self-control.
The tasks were designed to test how the previous act of choosing, or not choosing, affected peoples' ability to stay on task.
Those who earlier had made choices had more trouble staying focused and finishing the tasks compared to the participants who did not have to make choices.
"This pattern was found in the laboratory, classroom and shopping mall," Kathleen D. Vohs, the study's lead author, said in a release.
"Having to make the choice was the key. It did not matter if the researchers told them to make choices, or if it was a spontaneously made choice, or if making the choice had consequences or not."
In other experiments, participants were given math problems to practise for an upcoming test.
Those who had to make important choices selecting coursework for their psychology class spent less time solving the math problems and more time with distractions such as video games or magazines, compared to participants who were not asked to make choices prior to the test. The participants who made choices also got more math problems wrong than participants not faced with decisions.
Finally, the researchers conducted a field test at a shopping mall to see if their findings would hold up outside the laboratory.
Shoppers reported how much decision-making they had done while shopping that day and then were asked to solve simple math problems. The more choices shoppers made earlier in the day, the worse they performed. The findings held despite controlling for how long participants had been shopping, and for categories such as age, race, ethnicity and gender.
Even making "fun" choices had an effect on mental acuity. In their last experiment, researchers found that making enjoyable decisions, such as spending four minutes choosing items for a gift registry, was shown to be less mentally draining than when participants spent 12 minutes doing the same task.
The researchers concluded that even if people are having fun making decisions, their ability to focus is still being depleted with every choice they make.
