Answer:
Leon Festinger, Walter Mischel, and David Rosenhan were all influential psychologists who made significant contributions to the field of psychology.
Leon Festinger is best known for his theory of cognitive dissonance, which suggests that people experience psychological discomfort when their beliefs or attitudes are inconsistent with their behaviors.
Walter Mischel is known for his research on self-control and the marshmallow test, in which young children were offered a small reward immediately or a larger reward if they waited a certain amount of time.
David Rosenhan is known for his famous experiment in which he and several other research participants feigned symptoms of mental illness to gain admission to psychiatric hospitals and then observed the behaviors of the staff and other patients.
In summary, all three of these psychologists made significant contributions to the field of psychology and are well-known for their influential work