1. INTRODUCTION
METHODS
DISCUSSION
Activating the Biological and Behavioral Immune Systems
Julia Christensen & Matt Olson
Hamline University
RESULTS
Psychology recognizes two distinct facets of the immune
system: the biological immune system (BIO), covering all
processes of the typical immune system, and the behavioral
immune system (BEH), a set of cognitive, emotional, and
behavioral responses to environmental stimuli. Research on
this dual immune system indicates that each is capable of
influencing the other (Schaller & Park, 2011). For example,
perception of illness in others can activate the sympathetic
nervous system (Schaller, Miller, Gervais, Yager, &
Chen, 2010). Furthermore, evidence suggests that these two
systems are capable of influencing moral judgment (Inbar,
Pizarro, & Bloom, 2009). This study aims to further the
overall understanding of the BEH and the manner in which it
influences the BIO.
Participants:
• College students (26 women, 7 men, Mage = 20 years, age
range:18-27 years) recruited from Psychology courses at
Hamline University in exchange for extra credit.
Materials and Procedure:
The order of events is shown in Table 1. Participants were
randomly assigned a control group or experimental group.
Each completed two questionnaires (acclimation and
disgust scenarios), participated in a computer face detection
task , and donated two saliva samples. Results from the
saliva samples were not able to be analyzed.
•The results indicate that sick faces are evolutionarily
significant stimuli which draw upon subconscious focus.
This agrees with the hypothesis and is supported by
previous research.
•There was no significant differences between the control
and experimental group on Questionnaire #2. This does not
support the hypothesis. Previous research does not support
this finding.
•The significant difference on Item #1 of Questionnaire #2,
however, indicates that a more sensitive questionnaire
might better demonstrate the effects of the BEH on moral
judgments. Research on the sensitivity of physiology and
the BIO to the influence of the BEH is still lacking. These
findings on the BEH have important social and medical
implications.
Control Experimental
Questionnaire #1 Questionnaire #1
Pre-saliva sample Pre-saliva sample
Questionnaire #2 Face detection task
Face detection task Post saliva sample
Post saliva sample Questionnaire #2
Face Detection Task:
Participants saw 32 matrices of four faces each. Each face set
contained one sick and three healthy appearing faces. All were
shown for 50 milliseconds with 7 seconds in between.
Participants were asked to point to the face that stood out the
most.
RESULTS
Presented at the Annual Meeting of the Midwestern Psychological Association, Chicago,IL, 2015
Figure 2. A z-test of proportions of the face detection task
determined that, the target face was detected significantly
above chance (25%). Target faces were noticed 41.9% in 34
trials times (z = 2.27, p < 0.01)
Figure 3. Participants taking Questionnaire #2 before the
face detection task significantly higher than those taking
it after as shown by t(32) = 2.225, p=.03
Table 1
Figure 1. Example of Face Sets in Face Detection Task