In some countries/cultures, letters of reference are handed out in a sealed envelope. The interview process involves taking lots of weak signals (you can't tel

In some countries/cultures, letters of reference are handed out in a sealed envelope. The interview process involves taking lots of weak signals (you can't tell much about a person by talking to them for ~30 minutes) and trying to take a hire/no hire decision. Every little thing contributes to this decision. When people give more importance to incorrect signals, you end up with a bias (which can end up reducing diversity in the work place).