System justification is a type of thinking where people believe that the current system or rules that are in place are good and should stay the same. For example, if the way things are today is unfair in some way, people may choose to not challenge it because they think that it’s the only way and that it’s better if we just keep things the same. It’s like when an adult has to follow rules even though they don’t make much sense - they do it because it’s expected of them and they think it’s the right way to do things.