People who are overconfident, especially those who think intelligence is fixed and unchangeable are likely to be bad decision-makers. Overconfidence can lead to overestimation of skills and knowledge and is a well-documented problem for motorcyclists, drivers, doctors and lawyers, according to the researchers.

Researcher Joyce Ehrlinger from Washington State University found that overconfident people have fixed mindsets and tend to skip out on hard parts of the tasks while dwelling on the easy ones. Meanwhile, those who think that intelligence is a quality that can be improved over time or those with the growth mindset tend to concentrate on the hard parts of the task.

Overconfidence Can be Harmful

The research, published in the Journal of Experimental Social Psychology, involved more than 200 students and three experiments.

Medical Daily notes that the first experiment was a multiple choice test. Ehrlinger and her colleagues found that those with fixed mindsets were more overconfident than the other group, which had a growth mindset. In the second study, fixed mindset students spent only a little time on difficult problems and were more overconfident than those with growth mindsets, who took their time on the hard parts of the second test.

In the final experiment, all groups, especially the fixed mindset group was forced to look at the difficult questions, which in turn shook their confidence. The other group was unfazed. This gave the researchers further evidence that overconfidence can stop people from learning.

"We know that students' beliefs about intelligence are very consequential in the classroom and that interventions that teach students a growth mindset lead to improvements in their grades," Ehrlinger said in a press release, per EurekAlert. 

"We also know that being overconfident keeps people from learning. You have to understand and acknowledge what you don't yet know in order to truly learn. This research suggests that part of why growth mindsets improve learning might be because they lead people to better understand what they do and what they do not know."

A Growth Mindset Can Help Offset some of Society's Complex Issues

According to Phys.org, the study was done for Washington State University's Grand Challenges Initiative to look at some of society's issues, particularly unequal opportunities and how to improve learning and education among the youth.

"We know that students' beliefs about intelligence are very consequential in the classroom and that interventions that teach students a growth mindset lead to improvements in their grades," Ehrlinger said. "Education is perhaps the best way to advance opportunity and emerging evidence suggests that the benefits of teaching a growth mindset for improving grades are particularly strong for students in stigmatized groups based on race or gender."