A sign of a good thinker is someone who follows the evidence, even when their "tribe" is going in a different direction.

Too often our opinions on difficult topics sway along with the tribe we belong to.

A sign of a poor thinker is, as my friend @BStulberg says, someone who is: "Smart enough to convince themselves they're right. But not smart enough to realize they are convincing themselves they're right."

It’s not that your moral views determine which group you belong to, it’s the other way around.

Your tribe does more to determine your morality than your morality does to determine your tribe.

As a group of researchers summarized the science: “We will switch our moral compass depending on how it fits with what we believe politically.” https://onlinelibrary.wiley.com/doi/abs/10.1111/ajps.12448

A good self check is to ask yourself is there any topic where you disagree with your tribe.

Be it a religious, political, business, or whatever tribe. Can you identify topics where you hold opinions counter to the majority in that tribe?

If not, that might be a sign...