What psychological phenomenon can cause a witness to provide an expected or assumed answer?

The concept of expectancy plays a significant role in how witnesses interpret and recall events. When witnesses encounter a situation where they believe they know what the expected or correct answer is, their responses can be heavily influenced by these preconceived notions. This phenomenon occurs because individuals often conform their memory and perception to align with what they believe to be anticipated or accepted answers, thus shaping their testimonies.

Expectancy can lead to the reinforcement of biases that may skew the accuracy of the information recalled. This interplay between expectation and memory can result in witnesses inadvertently providing answers that conform to what they believe others are looking for, rather than based on their actual recollection of events. As a result, their statements may reflect these assumptions rather than objective reality.

In terms of other choices, confidence bias relates to a person's self-perceived accuracy in their answers, which does not necessarily involve expectation. Memory distortion pertains to changes in how memories are recalled over time, while post-event misinformation specifically highlights how information obtained after an event can alter a person's recollection of that event. However, expectancy is more directly tied to the leaning towards providing answers that fit expected responses at the moment of recall.