Cronyism

In the academic psychological community the tendency towards Cronyism the partiality to long-standing friends, is a mechanism which bolsters scientific orthodoxy.

Psychologists are after all people and are subject to the same social and group dynamics as others.

The psychological tendency for people to trust and like people with similar views as themselves means that they aggregate in social groupings which influence and underpin the social structure of the scientific community.

So for example the board of journals, lists of reviewers etc are often drawn up with these forces at work and as a consequence biases, subtle or otherwise can be  introduced into the intellectual fabric of the discipline.