The Outgroup Homogeneity
Effect: What happens when
Faces are Angry?
Mark Schaller
University of British Columbia
Thank you








Josh Ackerman
Jenessa Shapiro
Vaughn Becker
Vladas Griskevicius
Jon Maner
Steve Neuberg
Doug Kenrick
Research supported by U.S. National
Institutes of Health
The outgroup homogeneity
effect: Definition

“The tendency to perceive members of
an out-group as “all alike” or more
similar to each other than members of
the ingroup” (Baron, Byrne,
Branscombe, 2006, 11th edition).
Examples of the outgroup
homogeneity effect



People rate students from another university
as more homogeneous than students at their
own university (Rothgerber, 1997).
This can reverse (creating “in-group
homogeneity”) among some minority groups
seeking a strong sense of solidarity within
their ingroup (Simon & Pettigrew, 1992).
Eyewitness identification (Anthony, Copper, &
Mullen, 1992).
Functional perspective on
allocation of attention




Attention is a limited resource. It is
allocated selectively to things that
matter most (Schaller, Park, & Kenrick,
2007).
E.g., snakes (Ohman et al., 2001).
E.g., attractive women (Maner et al.,
2003).
E.g., ingroup members)
Angry faces


The face in the crowd effect (Fox,
Lester, Russo, Bowles, Pichler, & Dutton,
2000).
Angry faces are like snakes.
Hypothesis


When people are looking at neutral faces, we
will replicate the outgroup homogeneity effect
(Better recognition memory for ingroup faces
than outgroup faces.)
When people are looking at angry faces, the
outgroup homogeneity effect will be
eliminated and maybe even reversed (Better
recognition memory for outgroup faces than
ingroup faces).
Methods

Experimental Design: 2 (Target Race: Black,
White) x 2 (Target Expression: Neutral,
Angry) x 2 (Distracter: Present, Absent) x 3
(Presentation Duration: 500ms, 1000ms,
4000ms) mixed design. (Target Race and
Target Expression were within-participant
manipulations and Presentation Duration and
Distracter were between-participants
manipulations.)
Methods (continued)



One hundred ninety-two White
undergraduate students (117 male, 75
female) participated in exchange for course
credit.
Presentation stimuli included sixteen 5x3.5inch grayscale, front-oriented male faces
(Black/White, angry/neutral).
For participants in the Distracter-Present
condition, sixteen similarly sized grayscale
images of abstract art were randomly paired
with the faces.
Methods (continued)


Counterbalanced across participants, sixteen
new faces (Black/White, angry/neutral) were
employed as foils in the recognition memory
test.
Participants next watched a five-minute
distracter film clip before recognition memory
task (including previously-presented faces
and foils). For each photograph, participants
responded on a 6-point scale ranging from
“definitely did not see” to “definitely did see.”
Methods (continued)


Nonparametric signal detection measures of
sensitivity (A') and response bias (B''d)
(Stanislaw & Todorov, 1999; Donaldson
1992).
Analyses: 2 (Target Race: Black, White) x 2
(Target Expression: Neutral, Angry) x 2
(Distracter: Present, Absent) x 3
(Presentation Duration: 500ms, 1000ms,
4000ms) ANOVA on A’ and B”d.
Results (A’ and B’’d)


A’: 2-way Target Race X Target
Expression interaction: F(1,191)=44.90,
p<.001.
B’’d: 2-way Target Race X Target
Expression interaction: F(1,191)=70.43,
p<.001.
White
Neutral
Black
Neutral
White
Angry
Black
Angry
HR
FAR
A’
B”d
.677
.121
.844
-.406
.793
.421
.742
.371
.773
.223
.833
.022
.802
.178
.873
-.058
Effects of Processing Time and
Distractors on A’


A planned contrast comparing the Target
Race X Target Expressions interaction in the
most highly constrained condition
(500ms/distracter) to that in the least
constrained condition (4000ms/no distracter),
indicated a significant change in the strength
of the memory crossover, F(1,186)=4.51,
p<.05.
These results support the possibility that the
out-group heterogeneity effect for angry
faces may emerge primarily when processing
ability is limited.
Limitations






Only Male target faces.
Only Black/White target faces.
Only White participants.
Only angry faces.
Only university students as participants.
Only people from one culture as
participants.