By Thomas M. O’Toole, Ph.D.
Confirmation bias refers to when people accept or reject evidence based upon what they want to believe as opposed to basing it on the actual merits of the evidence. In some ways, it is a psychological survival mechanism tied to our beliefs about how the world works. Challenges to these beliefs can cause a great deal of chaos and stress, so our brains are, essentially, pre-programmed to seek out evidence that reinforces those beliefs, while minimizing, explaining away, or outright rejecting evidence that challenges them. In fact, this explains the siloed media we have today where people tend to pick which news channels to watch based upon their political affiliation.
For lawyers, confirmation bias can be a significant problem at trial, especially when the first impressions favor the other party. As Nobel prize-winning psychologist Daniel Kahneman notes, “The sequence in which we observe characteristics of a person is often determined by chance. Sequence matters, however, because the halo effect increases the weight of first impressions, sometimes to the point that subsequent information is mostly wasted.” In other words, first impressions at trial often shape how jurors perceive the subsequent evidence and testimony at trial. A poor first impression of the defendant will likely lead jurors to place greater focus and emphasis on evidence and testimony that reinforces the negative view of the defendant and vice versa. Continue reading