In one experiment, participants chose to either support or oppose a given sociopolitical issue. They were then presented with evidence that was conflicting, affirming, or a combination of both.
In all scenarios, participants were most likely to stick with their initial decisions. Of those presented with conflicting evidence, just one in five changed their stance. Furthermore, participants who maintained their initial positions became even more confident in the superiority of their decision—a testament to how influential confirmation bias can be.