Mr M shows a sign of stereotyping. Explain

In Act I, Scene III, when Isabel asks Mr. M if he has asked Thami about competing alongside her, he tells her that he has no intention of asking Thami, but rather, that he is going to tell him. When Isabel notes that his intent seems "dictatorial" (p.30), Mr. M replies that black South Africans adhere to more traditional hierarchies of age.