Agroup of students was told that their new teacher was humorous and easygoing. another group was told that he was rigid and hard to work with. the fact that the first group reported he was easygoing and the second said that he was rigid is an example of

the fact that the first group reported he was easygoing and the second said that he was rigid is an example of fundamental attribution error.

Explanation:

Fundamental attribution can be described as the tendency of other people to judge a person based on their behaviour but ignore the situations that might have caused a person to behave in that particular way.

For example, in the scenario discussed in the question the second group of children judged the actions of their teacher as rigid but did not think that the teacher might be rigid due to some undergoing problems.