1) The study investigated how the context of faces presented alongside a target face can influence perceptions of threat posed by the target face. 2) Participants completed a task in two runs where they judged faces on a spectrum from non-threatening to threatening. In run 1, the target face was paired with a young face, while in run 2 it was paired with an older face. 3) Results showed the target face was perceived as more threatening in run 1 when paired with the young face, compared to run 2 when it was paired with the older face. This demonstrates that threat judgments can be context-sensitive based on the other faces in the evaluation set.

1. Results
Threat Perception and Context Sensitivity Relation
Dan McDonald, Suhair Asi, and Spencer Lynn
Introduction
An individual’s judgment of how
threatening a face looks could be
altered by the context surrounding
that face. The idea of “context
sensitivity” has been studied as a
key aspect to the decision making
process. Context sensitivity argues
that when there is a collection of
options from which the decision
maker must choose then the
alternative options within the
collection compromise a unique
context (Busemeyer, 1993).
In Busemeyer's study, he noticed
this issue when studying economic
decision making. Subjects were
asked to choose between a gamble
and a certain value. Option A was
win or lose 5 cents with equal
probability. Option B was the win or
lose 50 cents with equal probability.
Option C was a certain loss of 1
cent. Option D was a certain gain of
1 cent. The probabilities of choosing
A over C, B over C, A over D, and B
over D were found: the probability
was higher to choose A over C than
B over C. These results would imply
that the probability to pick A is
always greater than B. However,
this was not the case; the pattern
was reversed for the A vs. D and B
vs. D choices. This meant that the
participants made the decision
based on the pairings rather than
on a preference for a specific
option.
From Busemeyer’s findings, we
hypothesized that a person’s
judgment of a face being
threatening would be influenced by
the other faces that one was also
judging. The set of faces under
consideration might form a context
that can influence one’s perception
of a target face.
References
Busemeyer, Jerome R., and James T.
Townsend. "Decision Field Theory: A
Dynamic-cognitive Approach to
Decision Making in an Uncertain
Environment." Psychological Review
100.3 (1993): 432-59.
Olivola, C. Y., Funk, F., & Todorov, A.
(2014). Social attributions from faces
bias human choices. Trends in
Cognitive Sciences, 18(11), 566-570.
Methods
Our study examines participants’
ability to effectively categorize two
different faces during a threat
perception task. We recruited 28
participants from the Northeastern
University student-body population.
Participants saw two different series
of faces that ranged from non-
threatening physiognomy (i.e., the
shape of facial features) to
threatening physiognomy.
According to previous research,
certain facial features create a more
threatening look than others, for
example, a stronger jaw line is more
threatening than a rounded or
weaker one (Olivola, 2014). Faces
were constructed using FaceGen
Modeler software. Each face series
comprised 11 “morphs” of a “base”
face. With each morph, facial
features changed very slightly, in
almost unnoticeable distinctions.
For example, the size of the
individual’s nostrils went from very
small to very large. The faces
ranged from 1-11, one being the
most non-threatening and 11 being
most threatening.
In run 1 of the experiment the face
series were created from two young
base faces. In run 2 of the
experiment an old base face was
used in place of one of the young
base faces. The two young faces
were approximately 20-30 years of
age while the old face was
approximately 50-60 years of age.
During the perception task,
participants viewed one face at a
time for 500 ms. Participants
earned or lost points by correctly
detecting whether or not the face
was threatening. They were
instructed to earn as many points
as they could over 300 trials. The
point values favored a conservative
bias, which means a tendency to
categorize the faces as not
threatening. Therefore, participants
with a more conservative bias
earned more points during the
study.
Conclusion &
Discussion
The threat physiognomy’s
dependency on a stimulus’
surroundings upholds Busemyer’s
(1993) findings of context sensitivity
because the choices surrounding
each stimulus influence the
participant’s perception and
ultimately his or her decision. While
conducting the threat physiognomy
study, a person’s threat perception
was affected by other options
present. Threat perception
experiences this phenomenon
because an individual is affected by
context sensitivity when analyzing a
threat, making Busemyer’s (1993)
findings applicable.
Though successful in identifying
context sensitivity, our experiment
is limited by the demographics of
the participants (solely Northeastern
Students with an average age of
18-22 years) and the type of stimuli
(only white males). Future studies
would ideally study faces of both
genders and different races, and
the studies should select a larger
variety for the demographic of
participants.
Currently, we are investigating how
adding an additional stimulus to the
face perception task would intensify
or hinder a person’s threat
perception. Context sensitivity is
applicable to a person’s threat
perception and would need further
investigation to determine if the
relation can be applied to all
settings.
Abstract
Social threat perception is the ability
to effectively identify person as a
threat or not. We investigated
whether or not people’s evaluation
of a face as threatening is biased by
other faces they are also
evaluating. Over two runs of the
experiment, participants had to
judge three faces that were similar
in features and state “yes” or “no”
when asked if they were
threatening. Participants earned
and lost points for correct and
incorrect categorization of the
faces, and were instructed to earn
as many points as they could. With
the points as motivation, a slight
bias to categorize faces as not
threatening would maximize
earnings. We hypothesized that the
participants would not judge the
target face, which was present in
both runs, any differently when it
was paired with another face, which
differed on the two runs. However,
participants judged the target face
to be more threatening when it was
paired with a young face (run 1)
than when paired with an old face
(run 2). These results show that the
participants were judging the two
faces in relation to each other rather
than separately. We conclude that
context sensitivity, meaning people
use everything in the situation to
form judgments, altered how people
perceived the target face.
We created the graph using the results from each participant (n=14). The data collected is
averaged to display the function of the participants' behavioral response to the target face
series. The calculations were determined by calculating the participants’ average portion of
times they said the target face was threatening. The graph displays the participants’
responses to the the target face (blue) and alternative face (green). A line’s inflection point is
the participants’ threshold of threat detection
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ProbabilityofperceivedThreat
Range of faces from non-threatening to threatening
Run 1
Target Face, Run1
Altered Face, Run 1
We created an aged version the target face series to see if an aged version would stimulate a
different response. Initially, we thought the aged face would be seen as less threatening due
to its age (50-60 years old), but the aged face was perceived as more threatening in
comparison to the target face. The graph represents the participants’ responses when
stimulated with the target face (red) and the aged alternative face (green) (n=14).
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ProbabilityofPerceivedthreat
Range of faces from non-threatening to threatening
Run 2
Target Face, Run2
Aged Target Face, Run2
By comparing both target face graphs side by side, we were able to conclude that the threat
perception of the target face was context sensitive, which makes the stimulus dependent on
the other stimuli surrounding the target face. The threshold determines where the participant’s
perception of the faces shifts from non-threatening to threatening. When comparing the two
data sets, the target face’s threshold location increased during Run 2. Participants found the
target face to be significantly less threatening when it was paired with the aged face in Run 2
than when it was paired with the young face in Run 1 (t25=-5.2, P<0.001).
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ProbabilityofperceivedThreat
Range of faces from non-threatening to threatening
Run 1 and Run 2 Results
Mean Target Face, Run 1
Mean Target Face, Run 2
McDonald, D., Asi, S., and Lynn, S. K. 2015. Threat perception and context sensitivity relation. Presented at the Fall
Symposium of the Interdisciplinary Affective Science Laboratory, Northeastern University, Boston, Massachusetts.