Mary is a graduate student studying to be a psychologist. the schooling is quite rigorous, and the academic pressures are high. for some reason, the competition between classmates is intense. mary's overall attitude, however, is that of a positive outlook. she believes that she will finish school soon and will do well in the process. she also expects that she will learn how to be a successful psychologist. based on this scenario, mary seems to demonstrate the quality of _____, which has been shown to somehow buffer the effects of stress and illness.