It perhaps stands to reason that when we’re highly confident in our beliefs and our decisions, we’re less likely to absorb information that might contract them, but nonetheless, new research from University College London highlights just how pervasive this phenomenon is.  The study aims to highlight the neural processes that underpin the confirmation bias that riddles so many of our thought processes.

“We were interested in the cognitive and neural mechanisms causing people to ignore information that contradicts their beliefs, a phenomenon known as confirmation bias. For example, climate change sceptics might ignore scientific evidence that indicates the existence of global warming,” the researchers explain.  “While psychologists have long known about this bias, the underlying mechanisms were not yet understood.”

The study asked volunteers to judge whether a cloud of dots was moving to the left or to the right of a computer screen, before giving a confidence rating for their answer of between 50% and 100%.  After making their initial decision, they were then shown the dots again and asked to make a final decision.  On this second round, it was made clear that people could change their mind if they felt they’d made a mistake.

Alas, those who were highly confident the first time round, seldom made use of this opportunity.  When a number of the volunteers underwent the experiment in a magnetoencephalography (MEG) brain scanner, it became clear quite why that was.

Decoding certainty

The analysis revealed that when people weren’t confident in their initial choice, they were better able to integrate new information, but that wasn’t the case when they were initially highly confident, after which their brains were practically blind to any information that contradicted their initial choice.

What’s more, the researchers believe that this phenomenon may be even stronger in real life, as our beliefs tend to be more important to us than the movement of a dot on a screen.

“Confirmation bias is often investigated in scenarios that involve complex decisions about issues such as politics,” the researchers say. “However, the complexity of such opinions makes it difficult to disentangle the various contributing factors to the bias, such as wanting to maintain self-consistency with our friends or social group.”

Polarized views

The researchers had previously found that this tendency was especially strong in terms of political beliefs, with those of us holding radical political views poor at knowing when we’re wrong, even on issues that are unrelated to politics.

The paper explains that the neural pathways we use when making a perceptual decision are pretty well understood, so it makes it possible for us to monitor the specific processes the brain goes through each time.  The researchers hope that a better understanding of the precise brain processes involved in the confirmation bias might help us to better overcome it.

“These results are especially exciting to me, as a detailed understanding of the neural mechanisms behind confirmation bias opens up opportunities for developing evidence-based interventions,” the researchers conclude. “For instance, the role of inaccurate confidence in promoting confirmation bias indicates that training people to boost their self-awareness may help them to make better decisions.”