How people think about themselves and their roles is caA group of students was told that new teacher humorous easygoing. Another he rigid hard to work willed?

The way people think about themselves and their roles is significantly influenced by self-perception and social perception. In the scenario you describe, the students' pre-existing beliefs and expectations about teachers (and perhaps even about humor and rigidity) will heavily influence how they perceive and interact with the new teachers.

* Self-fulfilling prophecy: The students' expectations, based on the descriptions ("humorous and easygoing" vs. "rigid and hard-willed"), will likely shape their interactions with the teachers. They might unconsciously behave in ways that confirm their initial impressions. For example, students expecting an easygoing teacher might be more relaxed and participatory in class, potentially leading the teacher to be more relaxed in return. Conversely, students anticipating a rigid teacher might be more apprehensive and less engaged, potentially reinforcing the teacher's perceived rigidity.

* Stereotyping and schemas: People use mental shortcuts (schemas) to organize information about the world. Pre-existing schemas about teachers (e.g., "good teachers are kind and understanding") and personality traits (e.g., "rigid people are difficult to deal with") will influence how the students interpret the teachers' behavior.

* Confirmation bias: Once students form an initial impression, they might tend to notice and remember information that confirms their belief while overlooking contradictory evidence. If a student believes a teacher is rigid, they might focus on instances of strictness and ignore instances of flexibility.

* Social comparison: Students might compare the new teachers to previous teachers or to each other, further shaping their perceptions and influencing their self-perceptions within the classroom dynamic (e.g., "I'm a better student in this class because the teacher is more approachable").

In short, the descriptions given to the students will act as a prime, influencing their subsequent perceptions and interactions with the teachers. The teachers' actual behaviors will certainly play a role, but the students' pre-existing beliefs and expectations will significantly color their interpretation of those behaviors.