Robin Hanson lists "signs that your opinions function more to signal loyalty and ability than to estimate truth":
You find it hard to be enthusiastic for something until you know that others oppose it. You have little interest in getting clear on what exactly is the position being argued. Realizing that a topic is important and neglected doesn’t make you much interested. You have little interest in digging to bigger topics behind commonly argued topics. You are less interested in a topic when you don’t foresee being able to talk about it. You are uncomfortable taking a position near the middle of the opinion distribution. You are uncomfortable taking a position of high uncertainty about who is right. You care far more about current nearby events than similar distant or past/future events. You find it easy to conclude that those who disagree with you are insincere or stupid. You are reluctant to change your publicly stated positions in response to new info. You are reluctant to agree a rival’s claim, even if you had no prior opinion on the topic. You are reluctant to take a position that raises the status of rivals.
There are more.