Imagine you did something really embarrassing in front of your mom and dad. Maybe you spilled milk all over the dinner table or accidentally knocked over a vase. You would feel really silly and ashamed, right?
Now let's say years later, when you are a grown-up, a stranger asks you about that embarrassing moment in front of your parents. You might not want to talk about it because it still makes you feel a little embarrassed.
Well, the criterion of embarrassment is kind of like that. It's a way that people who study history look at certain stories or events to see if they are true or not.
Basically, if someone shares something embarrassing or negative about themselves or someone they admire, it's more likely to be true. Why? Because if it wasn't true, they probably wouldn't have shared it!
For example, let's say there is a story in history about a really important king. The story says that when he was a kid, he used to wet the bed. That might seem like an embarrassing thing to include in a story about such an important person, right? But because it's embarrassing, it's more likely to be true. If someone made up the story just to make the king look bad, they probably wouldn't have included something embarrassing like that.
So the criterion of embarrassment is like a way to help people know if the stories they hear about history are true or not. If someone shares something embarrassing, there's a good chance it's real!