Scientific bias

Scientific bias is the assumption that a theory is true or false without evidence one way or another, or the attempt to dismiss or discourage research efforts to confirm or deny the theory - often on political or ideological grounds.

The American Psychological Association, for example, opposes reparative therapy for homosexuals (even if they volunteer for it, although they themselves acknowledge that there's no proof it does any harm:

• ... there are no scientifically rigorous outcome studies to determine either the actual efficacy or harm of "reparative" treatments. Association of Gay and Lesbian Psychiatrists