Final answer:
Making assumptions, often stemming from stereotypes and prejudice, can significantly hinder communication as it leads to biased treatment and acts as a barrier to open, unbiased interactions.
Step-by-step explanation:
The factor that can be an obstacle to communication and is defined as "anticipating situations and people all the time" is making assumptions. To make an assumption means that one is accepting something to be true without evidence or proof. This often involves overgeneralized beliefs about a group of people, known as stereotypes, which can lead to prejudice. Holding stereotypes and harboring prejudice may result in biased treatment and impede open and effective communication. For example, believing that individuals from certain age groups or cultural backgrounds possess specific attributes without really knowing them individually is a form of making assumptions that can severely obstruct productive interactions. Therefore, it is crucial to view others as individuals first, reduce language bias, and approach each communication without preconceived notions.