Editing Group dynamics (section)

====Contact hypothesis (intergroup contact theory)====
In 1954, [[Gordon Allport]] suggested that by promoting contact between groups, prejudice can be reduced.<ref>{{cite book | last = Allport | first = Gordon | title = The Nature of Prejudice | publisher = Addison-Wesley Pub. Co | location = Reading | year = 1979 | isbn = 978-0-201-00179-2 }}</ref> Further, he suggested four optimal conditions for contact: equal status between the groups in the situation; common goals; intergroup cooperation; and the support of authorities, law, or customs.<ref name=Pettigrew>{{Cite journal | last1 = Pettigrew | first1 = T. F. | last2 = Tropp | first2 = L. R. | doi = 10.1037/0022-3514.90.5.751 | title = A Meta-Analytic Test of Intergroup Contact Theory | journal = Journal of Personality and Social Psychology | volume = 90 | issue = 5 | pages = 751–783 | year = 2006 | pmid =  16737372| s2cid = 14149856 |author-link1=Thomas F. Pettigrew (sociologist)}}</ref> Since then, over 500 studies have been done on prejudice reduction under variations of the contact hypothesis, and a meta-analytic review suggests overall support for its efficacy.<ref name=Pettigrew/> In some cases, even without the four optimal conditions outlined by Allport, prejudice between groups can be reduced.<ref name=Pettigrew/>