Dehumanizing the Lowest of the Low Neuroimaging Responses to Extreme Out-Groups Article by Lasana T. Harris & Susan T. Fiske By Stephanie Clogg

Summary: Introduction Method Results Discussion My opinion on the paper

Introduction Aim: To investigate through neuroimaging if extreme out-groups are perceived as less than human Prejudice is not just a simple animosity! Out-group Infrahumanization Theory Medial prefrontal cortex (mPFC): necessary for social cognition Activated when thinking about a person or making social judgements - mPFC was activated differentially for social vs non-social cognition. For example, when people were required to make social judgements of people rather than an object. - Prejudice is not a simple animosity! As you will see, there is a wide variety of factors come into play when forming different stereotypes. - Further support comes from the out-group infrahumanization theory, where dehumanized groups are believed not to experience complex human emotions, morals, or share in-group beliefs. - Why do this study? This study is valuable since there is elusive concrete research done to support these theories, since past studies mainly relied on self report which is susceptible to socially desirable responding. Also, with prejudice as a familiar occurrence in the world around us, it is valuable to study what actually happens when perceiving those not within our “in-group”

Stereotype Content Model (SCM) High vs. low levels of perceived warmth and competence 4 stereotype dimensions (Pity, Pride, Disgust, Envy) SCM predicts extreme out-groups (low warmth/low competence) will be dehumanized Competence Low High Pity (elderly, disabled) Pride (middle-class, athletes) Disgust (homeless, addicts) Envy (rich people, money) Stereotyping involves a combination of emotions, not simple a dislike to a certain person due to their membership to a group or race. 4 warmth X competence clusters. Not all emotions are based on animosity! The low low group, disgust, relates to disliking and disrespect since it is believed that people in this group caused their negative outcomes. Disgust can target humans or non humans These extreme outgroups may be involved in the worst kind of prejudice: being excluded from humanity, percieved as sub-human Warmth

No significant mPFC activation Hypothesis: HYPOTHESIS: Extreme out-groups (low warmth/ low competence) may NOT significantly activate the mPFC No social cognition - not perceiving these groups as fully human??? Extreme out-group (disgust stereotype dimension) No significant mPFC activation Dehumanization!

Method: Participants: Scanning parameters: 22 Princeton undergraduates Included 6 ethnic minorities Scanning parameters: 3T Siemens Allegra head-dedicated MR scanner Participant responded with manual response pads Functional echoplanar imaging (EPI) sequence used Participants were familiarized with a similar task before entering scanner Series of 6 runs of 10 photos

Example of procedure for Study Group 1 Image of social group depicting 1 of the 4 SCM categories Example of procedure for Study Group 1 Pity Pride Disgust Envy Response screen Baseline fixation task Second image in series... 6 seconds Princeton University undergraduates viewed a large number of color photographs of different social groups (including Olympic athletes, business professionals, elderly people, and drug addicts), and images of objects (including the Space Shuttle, a sports car, a cemetery, and an overflowing toilet) that elicited the emotions of pride, envy, pity, or disgust. The four emotions were derived from the Stereotype Content Model (SCM), which predicts differentiated prejudices based on warmth and competence. Warmth was determined by friendliness, competence by capability. The two emotional extremes were pride and disgust; pride elicited high warmth and high perception of competence, and disgust elicited low warmth and low perception of competence. Envy and pity were considered moderate prejudices; envy elicited low warmth and high perception of competence, and pity elicited high warmth and low perception of competence. 2 seconds 12 seconds 6 seconds

Procedure: The details STUDY GROUP 1 (n=10) STUDY GROUP 2 (n=12) Affective assessments of images of SOCIAL GROUPS Affective assessments of images of OBJECTS 48 color images of 8 social groups 8 images of objects Each image depicts 1 of the 4 stereotype dimensions All images randomly sequenced for each run and run order was randomized Showed each image only once 8 images presented 3 times with 6 neutral filler photos each run Image shown for 6 seconds Image shown for 4 seconds Response screen shown for 2 seconds Response screen shown for 4 seconds After response, black screen with green cross in the centre was shown for 12 seconds before the next image In fMRI scanner, asked to decide which SCM quadrant each image belonged to. -Black screen was the baseline task later used for subtractive analysis

Results: Data analysis: BOLD signal response recorded from each SCM quadrant Subtracted activation during exposure to image from activation during black screen display (baseline task) Resulting contrast maps were averaged across participants Study 1 participants evaluated predicted SCM quadrant of image well above chance (0.25) Pride Envy Pity Disgust .70 .52 .83 .64

Brain regions involved: Study 1 Significant mPFC activations was revealed for pride, pity, and envy but NO significant mPFC activation for disgust Red circled areas indicate mPFC activation Results of a subtractive analysis of blood-oxygen-level-dependent (BOLD) activations in Study 1. Activation during fixation was subtracted from activation while participants viewed pictures of social groups representing the four quadrants of the stereotype content model (SCM). Results for the three SCM cells (pride, envy, and pity) showing significant activation in medial prefrontal cortex (mPFC) are shown here. The circled areas indicate mPFC activation. Positive t values indicate greater activation to the out-group pictures in the indicated quadrant, and negative t values indicate greater activation to the fixation cross. A 5 anterior; R 5 right. R=Right

Brain regions involved: Disgust No mPFC activation, supporting the hypothesis! Disgust images (in study) were associated with activation in the right amygdala &left insula In Study 2 (objects), only the envy category yielded small but significant mPFC activation Maybe because objects cannot elicit social emotions??

Discussion and summary: Due to absence of mPFC activation in low-low social groups, suggesting lack of social cognition, members of some social groups are dehumanized. Low-low social groups also ellicit neural patterns of disgust (insula) and fear (amygdala) according to meta-analyses The proof of neural mechanisms involved in dehumanization may help explain hate crimes and genocide

My Opinion on this study: Strengths: Using fMRI and EPI monitors activity in the whole brain, which allowed them to find activation in the left insula for disgust category. (This would not have been found if they were only looking at localized activation in the mPFC) Provided neurological evidence for previous theories Weaknesses: Low number of participants all from similar backgrounds and ages Further research: Use more people from different age groups, demographic and racial backgrounds.