The representativeness heuristic makes people judge likelihoods based on similarity to a stereotype rather than actual data. This can lead to base rate neglect, where people ignore important facts—like success rates or experience—in favor of a mental shortcut. As a result, decisions often become predictably biased rather than accurate.

Take Claire, a manager at a tech company. She needs to choose a team lead for a new project. Alex is confident and well-spoken, fitting Claire’s idea of a leader. Jordan, on the other hand, is quieter but has a strong track record in project management. Claire assumes that Alex’s polished demeanor means strong leadership skills—a classic representativeness bias—and picks Alex. Later, when teamwork issues arise, she realizes she overlooked Jordan’s actual qualifications.

In hiring, appearance and demeanor can sometimes hint at professionalism, but relying only on them can lead to bad decisions. For example, assuming someone in casual clothes is less competent than someone dressed formally can cause companies to hire the wrong people and overlook real talent. Judging based on surface traits rather than skills leads to wasted opportunities.

The representativeness heuristic makes people more prone to bias, like ignoring base rates or making assumptions that don’t hold up under scrutiny. Being aware of this helps people slow down and make smarter, more rational choices based on real evidence instead of first impressions.