Bias is a kind of prejudice, a tendency to believe something even when you can’t prove it’s true.
We all have biases. If you’ve been reading this site for a while, you’ve probably noticed that I have a strong anti-authoritarian bias. All other things being equal, I’m more likely to side with the people marching and yelling and setting things on fire than with the people trying to keep them in line. I don’t always agree with protesters’ motives/demands and I don’t think property damage is necessarily the best way to get a point across, but when I hear a riot has broken out, I assume there is a group of bastards somewhere who had it coming.
There all kinds of biases. Some people secretly believe members or your race or gender are by nature sneaky, greedy, lazy, bad drivers, bad dancers, and so on, and every time they see someone who looks like you acting that way, they count the memory as evidence that they’re right. You and I do the same thing with our own biases. I nod self-righteously whenever I hear about an authority figure exposed as a fraud.
That’s the dangerous thing about bias: It feels so right. If I’m honest, I have to admit that an angry mob is sometimes just a bunch of idiots with flaming torches — a public menace that won’t accomplish anything — and my squishy fondness for rebels and agitators makes it harder for me to dismiss their tactics.
If you want to know what’s true, you should be aware of how your own biases affect what you notice and how you think about the world and the people in it.