Decoding "us" and "them": Neural representations of generalized group concepts

Area of Science:

• Neuroscience
• Evolutionary Psychology
• Social Cognition

Background:

• Humans universally form social coalitions, yet neural representations of "us" and "them" remain unclear.
• Evolutionary theories propose a common neural code for group affiliation, irrespective of group type.
• Understanding generalized group concepts is crucial for social neuroscience.

Purpose of the Study:

• To identify the neural substrates of generalized social group representations.
• To investigate if the brain uses a common code for in-group and out-group concepts across different categories.
• To explore the role of specific brain regions in processing social group membership.

Main Methods:

• Multivoxel pattern analysis (MVPA) was employed to decode neural representations of social groups.
• A classifier was trained on neural data from arbitrary lab-created teams.
• The classifier's ability to generalize to real-world categories (political parties) was tested.

Main Results:

• The dorsal anterior cingulate cortex/middle cingulate cortex and anterior insula showed consistent representation of groups across categories.
• Cross-categorization classification was replicated in the anterior insula.
• Classification accuracy was primarily driven by accurate in-group target identification, suggesting in-group preference.

Conclusions:

• Social group concepts rely on domain-general neural circuitry involved in encoding functional significance.
• The anterior insula plays a significant role in generalized social group perception.
• Findings support theories emphasizing in-group preference in social cognition and perception.