James Surowiecki writes in his book The Wisdom of Crowds that diversity -- not in the sociological sense, but rather in the conceptual and cognitive sense has a profound effect on a groups ability to come to a decision. The hope with cognitive diversity is that the perspectives gained from individuals - who maintain their independent thought - can somehow contribute to a group getting the decision right.  

Social theorists contend that escaping from the influence of others or maintaining the independence - in a group setting in particular - is made difficult by our innate need to conform. Surowiecki argues that the more a group has influence on each other and the more the group communicates with each other, the more difficult it becomes for individuals within the group to maintain their independent thought. He further suggests that it becomes increasing difficult for a groups, especially a small one, that is constantly "connected" to make collectively intelligent decisions.

The suggestion here as it relates to recruitment is that the team selected to interview candidates should be conceptually and cognitively diverse. Furthermore, while it might feel good to have an interview team that one is "comfortable" with, this might not necessarily be the wisest path to the best candidate. Interview teams particularly small ones might be better served by inviting some new interviewers into the process.