We are blind to our own bias: Study

Almost evryone has a "bias blind spot," meaning that people are less likely to detect bias in themselves than others, however, how blind they are to their actual degree of bias may vary, new research says.

Believing that you are less biased than your peers has detrimental consequences on judgments and behaviours, the findings show.

"Our research found that the extent to which one is blind to her own bias has important consequences for the quality of decision-making," said study lead author Irene Scopelliti, a lecturer in marketing at City University London.

"People more prone to think they are less biased than others are less accurate at evaluating their abilities relative to the abilities of others, they listen less to others' advice, and are less likely to learn from training that would help them make less biased judgments," Scopelliti said.

For the study, the researchers ran five experiments -- the first two focused on testing whether bias blind spot differences is associated with traits such as IQ, general decision-making ability and self-esteem.

The final three studies examined consequences of individual differences in the bias blind spot, specifically its relation to how people make social comparisons, the weight people placed on advice from others and their receptivity to de-biasing training.

The most telling finding was that everyone is affected by blind spot bias -- only one adult out of 661 said that he/she is more biased than the average person.

"When physicians receive gifts from pharmaceutical companies, they may claim that the gifts do not affect their decisions about what medicine to prescribe because they have no memory of the gifts biasing their prescriptions," said one of the study authors Erin McCormick from Carnegie Mellon University in the US.

"However, if you ask them whether a gift might unconsciously bias the decisions of other physicians, most will agree that other physicians are unconsciously biased by the gifts, while continuing to believe that their own decisions are not. This disparity is the bias blind spot, and occurs for everyone, for many different types of judgments and decisions," McCormick added.

The study was published in the journal Management Science.