Answer:
situational influences; personal dispositions
Step-by-step explanation:
Situational influences refers to temporary condition that influence people's decision making while personal dispositions refers to concrete motives/principles that influences people's decision making.
People generally believe that we make our decisions (such as purchasing decision) based on personal dispositions along. But if situational influences are manipulated properly, it will influence other people without they even realizing it. This is why people often underestimate its impact.