Many factors determine whether a person will be successful in a job. Functional capability, language and social skills, cultural fit with a company, personal drive… assigning weights and scores on these factors to form a coherent picture of a candidate can become a complex problem in optimization.
When confronted by such a complex problem, the human brain substitutes it with a simpler and easily solvable one. The process or bias – called attribute substitution – developed as an evolutionary response to a hostile environment. Quick responses were needed to survive in our distant past (is a dangerous animal lurking in the Savannah?) and our brains developed intuitive processes to solve survival problems on the fly.
The world has dramatically changed in the last few thousands years but our neural processes developed over hundreds of thousands of years; they remain unchanged. Our brain is designed to make snap judgments. In an interview situation these intuitive processes can come unstuck.
What kind of attribute substitution can happen in an interview? The most common one is likeability. It is difficult to evaluate on a range of qualitative factors; likeability is a much easier problem to solve. All of us who interview candidates make this mistake (I like him therefore he will succeed in the job) with consequences that can be damaging for a company.
The human brain will constantly trick managers who rely on their intuition. The only solution is detailed listing of key success factors, an informed evaluation against these factors and an open discussion among the interview panelists.
This can be quite taxing for time-pressed senior managers; one solution is to let a quality search firm do the job for you.