Threat from similar outgroups drives more bias than threat from dissimilar ones.

Evidence

Distinctiveness threat is another type of threat related to social identity. According to social identity theory (Tajfel & Turner, 1986), people seek membership in positively distinct groups and threats to ingroup distinctiveness are therefore aversive. Intergroup comparisons with a very similar outgroup threaten group uniqueness and distinctiveness (Branscombe et al., 1999), therefore very similar groups may prompt more competitive intergroup comparisons leading to higher levels of intergroup bias. In this regard, Roccas and Schwartz (1993) manipulated the degree of intergroup similarity and found that as similarity increased, high identifying group members showed an increase in intergroup bias along dimensions relevant to the ingroup. — Blake M. Riek, Eric W. Mania, and Samuel L. Gaertner, Intergroup Threat and Outgroup Attitudes, 59

Categorization

• XREF: This bears directly on the MOC question: if an identity has few other foundations besides its exclusions, similarity-based distinctiveness threat should be maximal — analogous to Bauman’s ‘enemy in our midst’ being most anxiety-producing. — connects to: Threat effects on attitudes are stronger for low-status than high-status outgroups — Blake M. Riek, Eric W. Mania, and Samuel L. Gaertner, Intergroup Threat and Outgroup…, 129; Threat dynamics among status-equal groups remain unexamined. — Blake M. Riek, Eric W. Mania, and Samuel L. Gaertner, Intergroup Threat and Outgroup…, 152; Similarity of an outgroup raises bias only among highly identified ingroup members. — Blake M. Riek, Eric W. Mania, and Samuel L. Gaertner, Intergroup Threat and Outgroup…, 59 (+1 more)
• QUESTION: Is the ‘narcissism of small differences’ effect here strongest where the ingroup identity is otherwise thin or underdetermined?
• recurring: this claim recurs 2 times within its source

Related

• Groups very similar to the ingroup provoke more intergroup bias than dissimilar ones do. (similarity 0.95)
• Similarity of an outgroup raises bias only among highly identified ingroup members. (similarity 0.91)
• Recategorizing outgroup members as ingroup members diminishes perceived threat. (similarity 0.86)
• Group-based identity forces precede realistic and symbolic threat perception (similarity 0.85)
• In-group bias intensifies against similar rather than dissimilar out-groups (similarity 0.85)
• Threat dynamics among status-equal groups remain unexamined. (similarity 0.85)
• Threat to distinctiveness drives more complex identity structures, but evidence is sparse (similarity 0.85)
• Groups only compare themselves with relevant out-groups, not all available ones. (similarity 0.85)
• Distinctiveness threat may precede and amplify symbolic and realistic threats (similarity 0.85)
• Anticipatory loss of group standing drives outgroup discrimination (similarity 0.84)
• Perceived threat to group distinctiveness reduces social identity complexity (similarity 0.84)
• Ingroup bias rises when outgroups are similar and ingroup identification is strong. (similarity 0.84)
• Distinctiveness threat shifts behavior more than judgment, though its effect size is tiny. (similarity 0.84)
• Recategorization into a common identity can backfire and increase subgroup bias via distinctiveness loss. (similarity 0.83)
• Ingroup identification strength moderates whether group-level or individual-level threats drive attitudes. (similarity 0.83)