In a study by kotter and heskett, evidence is provided to support the claim that is important for performance.

- Managing cultural values.

Explanation:

As per the question, the study of Kotter and Heskett the evidence provided by them to substantiate their claim is that 'managing cultural values' is crucial to modify or direct one's performance. These values involve the ideals as well as fundamental propositions that shape the very belief system and conduct of a community and its actions(performance) morally and ethically. Therefore, the administration of these values would evoke an 'ethical and moral performance' from an individual. Thus, 'managing cultural values' is the answer.