Harris and Fiske (groups dynamic bio approach) human relationships

Aim:

To investigate how the brain reacts to extreme out-groups such as addicts or homeless people through the analysis of brain activity in the prefrontal cortex and amygdala.

Sample

22 undergrad students from princeton university (participants were randomly divided into conditions (viewing different categories of images)

Design

Lab experiment

Procedure

Participants first practiced identifying emotions on neutral images. Then placed into an fMRI scanner. They viewed sets of photographs in blocks (people vs objects). After each image, participants selected which emotion they felt (disgust, pity, envy, etc). Brain activity was recorded, focusing on areas such as the amygdala and prefrontal cortex.

Results

There was a clear difference found in the brain activity when participants viewed addicts or homeless people. The activation of the amygdala was seen, and their brains set off reactions associated with disgust. The insula (associated with non-human objects like garbage) was activated, while the medial prefrontal cortex (associated with social cognition) was not. The participants did not react to the homeless as people.

Evaluation (Strengths)

Standardized procedure that is highly replicable. Both men and women took part, widening generalizability.

Evaluation (Limitations)

Sampling bias: Princeton students often come from high socio-economic backgrounds and may be more inclined to view addicts or homeless people with higher levels of disgust due to socio-economic separation.

Connection to group dynamics and social identity theory

Supports the biological explanation of prejudice. Indicates that some social groups are dehumanized (absence of social cognition neural signature), which could explain the human ability to commit hate crimes or genocide.

Social Identity Theory

because the study shows how people react differently to certain out-groups, especially homeless people and addicts.

Participants showed brain activity linked to disgust, and the medial prefrontal cortex, which is usually active when thinking about other people, was not activated.

This suggests that extreme out-groups were judged as less human, showing out-group discrimination.

group dynamics

how group categories affect the way people think about and emotionally respond to others.

Since group dynamics includes conflict, communication, social roles, and group behavior, this study fits because homeless people and addicts were treated as low-status out-groups.

The study shows that group membership can lead to prejudice, unequal treatment, and emotional distance from people outside the in-group.

Real world application

Explains how crimes against humanity occur. .biological backing suggests that overactivation of the insula leads people to view others as "sub-human."