What causes resignation??

Generally speaking, people resign in games because they aren't willing to keep playing.

Some people might disagree with this. To counter their argument I'll say this:

- Why do you resign against a super strong player? It's because you think you can't beat them.

- Why do you resign against someone that keeps beating you? It's the same reason, pretty much.

- Why do you resign when a player much lower-rated than you are is up a piece or more? It's sometimes because you don't want to see yourself get humiliated through them checkmating you. Some people don't want others seeing that happen, because they would be embarrassed.

- Why do you resign when you see that checkmate is going to happen soon? It's because you think your opponent sees the checkmate also.