Final answer:
The friend is displaying hindsight bias by retroactively claiming that the outcome of the drawing was predictable and thus the correct number should have been known in advance.
Step-by-step explanation:
The friend in the scenario is engaging in hindsight bias, which involves the belief that an event was predictable after it has already occurred. This is often referred to as the 'I-knew-it-all-along' phenomenon, and it happens when people believe they could have predicted the outcome of an event after the outcome is known, despite not actually having predicted it.
Hindsight bias is a common cognitive bias that can affect how we perceive and remember events. When applied, people retroactively assign certainty to events that were, in reality, uncertain before the outcome was known. It often occurs when individuals evaluate the decisions of others, thinking it was obvious which choice should have been made.
Identifying this bias is crucial because it can lead to overconfidence and the misjudgment of one's own decision-making abilities, as well as the unfair assessment of others' decisions.