In this paper, I researched how aspects of personality can influence behavior; the specific example here is infidelity. I synthesized the data of multiple experiences to create a personality profile of a person who is more likely to cheat on a romantic partner than the "average" person.

1. COMPONENTS OF INFIDELITY 1
Components of Infidelity:
Who Is Most Likely to Cheat in Romance?
Kelly Burke
Saint Louis University

2. COMPONENTS OF INFIDELITY 2
Another field in which the tendency towards infidelity can be analyzed is the “social and
cultural domain,” which states that “personality affects, and is affected by, the social and cultural
context in which it is found” (Larsen and Buss 2014). A study done by Pham et al. examines
“coalitional mate retention,” or a process in which “individuals ask an ally to assist with
thwarting their romantic partner’s infidelity” (Pham et al. 2015). Because coalitional mate
retention involves the influence of the community and a tendency towards gendered norms, it
would fall under the category of social and cultural domain. In this study, Pham et al. aimed to
chart the correlation between the frequency in which participants “requested or received
coalitional mate retention” from both a male friend and a female friend, and the perceived quality
of each friendship (2015). The central question examined whether the amount of coalitional
mate retention requests correlated negatively or positively to the perceived quality of the
friendships, not accounting for the success of the actual retention process (Pham et al. 2015).
Examination of this correlation aims to determine whether coalitional mate retention is a
beneficial practice to the quality of an individual’s friendships. If it builds firmer bonds within a
society, it may be a behavior worth encouraging, as it has “solved sex-specific adaptive
problems” over the course of evolution; if it weakens friendships, however, then it should be
discouraged, as coalitional mate retention has been shown to correlate positively with instances
of allies becoming mate-poachers or otherwise sabotaging the reputation of a former ally (Pham
et al. 2015).
Pham et al. predicted that coalitional mate retention would correlate positively to a high
quality of friendship in relationships involving women: female-female, female-male, and male-
female (2015). The researchers formulated this hypothesis based on past studies showing that
women consider the sharing of personal information to be vital in the establishment and

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maintenance of platonic friendship, as such bonds are formed on trust and mutual confidence.
Coalitional mate retention fundamentally requires that the allies are open to each other about
themselves and their relationships, indicating that the sharing of personal information must take
place (2015). Coalitional mate retention was predicted to correlate negatively to male-male
friendships, as men do not usually share personal information due to a fear of reputational
damage, and are thus much less likely to open up about themselves without the encouragement
of a woman. Men are also less likely to request coalitional mate retention because a majority of
them consider it a sign of weakness or dependence running counter to their masculine ideal; it is
analogous to men’s refusal of health care under the same premises (Pham et al. 2015). Also,
men are more likely to become jealous of their male ally, especially because the “monopolizing”
of the observed partner’s time has the potential to develop into mate-poaching.
To observe the correlation between high quality friendships and coalitional mate
retention, Pham et al. administered the McGill Friendship questionnaire to 387 participants. The
questionnaire has six dimensions: Help, Intimacy, Reliable Alliance, Stimulating
Companionship, Self-Validation, and Emotional Security. The first three dimensions were
focused most closely, as current research supports that they have the greatest overall correlation
to coalitional mate retention (Pham et al. 2015). Of the 387 participants, 176 were women, and
all of the participants were involved in committed, heterosexual relationships which lasted at
least one year. Each participant reported on two of their heterosexual friends, one male and one
female, whom they had described as being close friends whom they had known for at least a
year. On a scale from 0-8, the participants would report “how often their friend fulfilled
friendship roles,” with 0 representative of never and 8 representative of always (Pham et al.
2015). Participants then completed the Coalitional Mate Retention Inventory for each friend; it

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was structured on a 0-3 scale and consisted of 44 items. The questions determined 1) how often
the participant requested the friend to partake in coalitional mate retention practices within the
past year and 2) how often the participant believed these friends actually fulfilled the request
(Pham et al. 2015).
To determine the results, Pham et al. calculated “friendship-quality variables from the
mean of responses to items” which fell into the Help, Intimacy, and Reliable Alliance categories.
The researchers then used the Coalitional Mate Inventory to calculate seven “coalitional mate
retention tactic variables” which were the “mean of responses to items comprising each tactic”
used while cooperating with an ally. These domains were: Manipulation, Praise, Vigilance,
Therapy, Gifts, Monopolizing Time, and Violence (Pham et al. 2015). The data was then placed
through two binomial tests, which examined all four friendship conditions: female-female,
female-male, male-female, and male-male. The first of the two tests “assessed the proportion of
positive correlations out of the 48 total correlations” while the second test “assessed the
proportion of statistically significant positive correlations out of the total number of statistically
significant correlations” (Pham et al. 2015).
Male-female friendships correlated positively to the use of coalitional mate retention,
with 41 of the 48 possible correlations being positive and 19 of the 19 statistically significant
correlations being positive. Female-male friendships also correlated positively to the use of
coalitional mate retention, with 46 of the 48 possible correlations being positive and 31 of the 31
statistically significant correlations being positive. Female-female friendship correlated
positively to the use of coalitional mate retention, with 45 of the 48 possible correlations being
positive and 21 of the 21 statistically significant correlations being positive. These statistics
supported the hypothesis of relationships involving women being more likely to involve the use

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of coalitional mate retention, as women are the impetus behind such behavior (Pham et al. 2015).
Male-male friendships, however, correlated negatively with the use of coalitional mate retention,
with 33 of the 48 correlations being negative, and 13 of the 16 statistically significant
correlations being negative as well. These findings are also consistent with the hypothesis, as
male-male friendships correlate negatively with the sharing of personal information; the lack of
women in the relationship prompts men to guard their dignity, even around male friends with
whom they have a high-quality relationship. Men are also more concerned about the possibility
of mate poaching, which correlates positively with coalitional mate retention (Pham et al. 2015).
Another factor to potentially consider is the difference between the ways which men and women
interpret close opposite-sex relationships. Men, for example, “perceive an intimate opposite-sex
friendship as a mate poaching opportunity” more so than women do, which might be a relevant
factor as to why men are typically less willing to engage in coalitional mate retention (Pham et
al. 2015).
There are a few problems with the study, however. For example, gender differences may
be inadequately accounted for in terms of how the participants actually spend time with their
same-sex friends, a flaw which the study itself admits. Men may spend more time with their
close same-sex friends than females do, which would leave less time for the men to actually
engage in coalitional mate retention. The study also admits that it suffers from the classical
correlational study loophole: does a precede b, or does b precede a (Pham et al. 2015)? Another
potential pitfall of the study is that the sample size only consisted of heterosexual participants.
Homosexual participants might consider their relationships in different ways than which
heterosexual participants might; for example, a gay man might feel more comfortable being more
open with information than a straight man because he might not feel constrained by a

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heteronormative masculine ideal. Homosexuals could be incorporated into the heterosexual
sample size, or the same experiment could be performed again on a homosexual population to
determine how societal gender roles influence concept of friendship and coalitional mate
retention.
This study was valuable for defining the ways in which men and women classify the
closeness of their friendships and how this, in turn, correlates with their sexual tendencies. It
was not surprising to learn that women are more likely to engage in coalitional mate retention
when reflecting upon gender norms. These norms typically expect women to behave in a more
community-oriented manner, which extends to their sexual practices. The male-male results also
aligned with gender norms, as men are expected to be more individualistic and capable. This
ideal masculinity ties into the tendency for males to behave more unfaithfully than females, as
they view friendships as a gateway to intimacy in many cases. Thus, this study can be said to
show that men are more likely than women to commit infidelity, and are less likely to help others
avoid unfaithful behaviors due to the advantage they may gain from a potential mate-poaching.
Infidelity can also be studied within the adjustment domain, which states that
“personality plays a key role in how we cope, adapt, and adjust to the ebb and flow of events in
our day-to-day lives” (Larsen and Buss 2014). It typically relates to one’s physical and mental
health when faced with a variety of stressors, and is thus often invoked in cases of mental illness.
A 2015 study done by Ein-Dor et al. falls under the adjustment domain, as it focuses on how men
and women cope with threats of mate-poaching. The study was generated to test the “rivalry
centered hypothesis,” which posits that women are generally “more sensitive to cues of infidelity
than men are,” tending to “focus their attention on potential rivals in their mate's vicinity.” Men,
on the other hand, are more likely to monitor their own partner for signs of infidelity and focus

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less on potential rivals, a behavior which has recently been postulated to be unique to their sex.
This implies that although men and women generally adopt different strategies for dealing with
mate-poaching, they have the same ultimate goal: mate retention (Ein-Dor et al. 2015). By
monitoring their partner’s behavior, men and women can attempt to prevent a “defection” and
subsequent break in the relationship. These behaviors have evolved because infidelity, which
occurs at fairly high rates within the population (about 22–25% of men and 11–15% of women),
is typically very destructive mentally, physically, emotionally, and financially (Ein-Dor et al.
2015).
In the rivalry-centered hypothesis, women were “expected to show overall higher
infidelity-detection sensitivity than men” because their coping strategy involves monitoring
multiple persons, whereas men’s coping strategy only focuses the attention on their mate. These
coping strategies are believed to be due, in part, to evolutionary mechanisms, as men can
physically coerce their partner into obeying them, whereas women are typically not strong
enough to use this same tactic against their male partners. Thus, they must adopt a preventative
strategy aimed at nixing infidelity before it can occur, or to prevent an existing extra-
monogamous relationship from progressing any further (Ein-Dor et al. 2015).
To test the rivalry-centered hypothesis, the researchers set up four different smaller
studies, using the combined results to test their theory. The first study “examined whether men
and women differ in the extent to which they appraise ambiguous partner-related incidents as
comprising a threat of infidelity.” 194 participants (80 men and 114 women) “completed self-
report measures of partner distrust, history of infidelity, and socio-economic status” and then
were asked whether or not they believed if a “partner-related event” indicated a distinct threat
towards infidelity; the questions were set up in a yes-no format. Women were hypothesized to

8. COMPONENTS OF INFIDELITY 8
judge more events as a threat towards infidelity than men, as past studies have shown that
women are more likely than men to mistrust their romantic partners (Ein-Dor et al. 2015).
Participants first completed a 5-item self-report measuring “the extent to which they tend to
mistrust romantic partners.” The self-report was set up with a scale from 1-7 with one being “not
at all” and 7 being “very much.” After the questionnaire was completed, participants were
instructed to read 11 vignettes depicting “ambiguous signs of partner unfaithfulness” and were
then asked whether or not the situation constituted infidelity. The researchers totaled the amount
of vignettes that were affirmed to be portraying infidelity for each participant. Once all the
vignettes had been categorized as situations of infidelity or not infidelity, the participants were
asked “Did one of your past or present romantic partners ever commit an act of sexual
infidelity?” and “Were you ever involved in a romantic affair while in a committed
relationship?” (Ein-Dor et al. 2015).
More women than men reported that their partner had cheated on them, which correlates
to the higher rate of women perceiving infidelity; a person who has been cheated on is more
likely to be more aware of the same cues in a different setting. More women also considered the
vignettes to be depicting sexual infidelity than men, affirming the initial hypothesis that men are
more likely than women to interpret ambiguous situations as infidelity. Study 2 was designed to
test whether women were more accurate at depicting infidelity than men, or whether their
suspicions were actually false alarms. The sample size of Study 2 was 118 heterosexual adults
(44 men and 74 women); about twenty-five percent reported that a current or past partner had
been unfaithful to them, while about thirty-eight percent admitted that they were “involved in a
sexual affair” (Ein-Dor et al. 2015). Participants in this study were asked to identify a picture
representing infidelity as quickly as possible from “a matrix of control pictures.” After the

9. COMPONENTS OF INFIDELITY 9
picture was correctly identified by being clicked on by the participant, the matrix would change
and they would have to locate a different infidelity picture. The timing ranged from 2-22
seconds to identify the picture, while the number of attempts to select the correct picture ranged
from 1-17.
On average, women detected the infidelity pictures more quickly than men and made
fewer errors. These findings affirmed the hypothesis that women detect romantic threat more
quickly and with greater accuracy then men. To affirm that women were indeed more skilled at
detecting romantic threat and not threat in general, Study 3 was implemented. The sample
population of Study 3 consisted of 93 heterosexual participants (47 men and 46 women). The
participants first completed the test described in Study 2 and then completed an additional test,
which asked them to identify the picture on a matrix which represented danger from a poisonous
animal. Once again, women scored lower times and fewer errors than men on the infidelity
identification, but both women and men scored about equally on the poisonous animal detection
test. This confirms the hypothesis that women detect infidelity quicker and more accurately than
men, and that the skill is situation-specific, not applying to all instances of danger (Ein-Dor et al.
2015). Study 4 was designed to test the final part of the hypothesis, namely, the theory that
women focus more closely on potential romantic rivals than men do. Participants were first
asked to complete a self-report measuring “partner distrust, history of infidelity, and socio-
economic status,” and were then asked to complete a computerized classification task, which
measured the participants’ “perception of within-couple threats and threats that reside outside of
the relationship.”
The sample size consisted of 127 heterosexual participants (60 men and 67 women). Ten
percent of the sample reported an unfaithful partner while thirteen percent reported that they

10. COMPONENTS OF INFIDELITY 10
were involved or had been involved in a romantic affair. The participants first completed the
spousal distrust questionnaire, and were then tasked to complete another visual test. In this
variation, a couple was seated at a bar, and an attractive man or woman was seated close by. The
first phase of the test examined the detection of within-couple infidelity, and the series of
pictures portrayed one member of the couple looking at his or her significant other, looking at an
indeterminate point in space, or looking passionately at the attractive stranger. Participants were
asked to evaluate the possibility that the partner would stray based on his or her level of eye
contact. In the second phase, the participants were asked to evaluate the threat of infidelity from
outside the relationship. Physically attractive women and dominant males were used as the
outside threat in this picture series, as these are traits which each gender finds most threatening
to mate retention. Participants were asked to indicate whether the desirable person was looking
at one member of the couple and whether or not this presented a threat to mate retention. In the
first phase, pictures which depicted ambiguous gaze direction evoked responses that “men were
significantly more likely than women to state that the target's partner was looking at the
attractive stranger,” presenting a within-relationship threat to mate retention. This affirms the
hypothesis that men are more likely to guard their own mate than to focus on external threats. In
the second phase, “women were significantly more likely than men to state that the attractive
stranger was looking at the target's partner,” except in the non-ambiguous situations. Study 4
affirms the initial hypothesis positing that women are more likely to be concerned with same-sex
rivals outside of the relationship, whereas men are more likely to keep watch over their own
partner.
While the studies successfully supported the hypothesis, there were a few problems with
the studies. As the researchers admit, the studies solely examined the participants’ ability to

11. COMPONENTS OF INFIDELITY 11
detect infidelity within other people’s relationships, not within their own. Detecting infidelity
without the benefit of being an outsider is considerably more difficult, and future studies should
address this disparity when accounting for overall detection ability. Also, in Studies 1 and 2, the
sample size of women significantly outnumbered the sample size of men, which could skew the
results in favor of women’s detection abilities. Lastly, the four components of the larger
hypothesis utilized different persons for the sample population. Thus it lacks within-subject
testing although all the studies were essential to test the same hypothesis.
This article confirms that it is much easier for a man to cheat than for a woman to cheat.
While men only have one partner to observe, women have to watch multiple targets, so the
chance of them missing a cue is greater even though they are overall more able to detect
infidelity. Because men have a greater ability to successfully engage in infidelity, they are more
likely to actually do so. Also, it confirms that although men and women face the threat of
infidelity in different ways and in different frequencies, both are equally affected emotionally
and mentally. Thus both strive to avoid infidelity and retain their partner despite living in a
culture which normalizes extramarital relationships to a certain extent. It will be interesting to
see whether perceptions about infidelity change if the rates continue to grow over time.
Taking all four studies into account, one can conclude that unmarried men with high
levels of social confidence, who have also been unfaithful in the past, are more likely to commit
infidelity than women. The first study examined infidelity intentions, which posited that persons
with a positive outlook on infidelity are most likely to actually carry through with unfaithful
behavior, as beliefs are thought to correlate closely with realized actions (Jackman 2014).
Persons who view themselves as more in control of their behavior and their social situation are
also more likely to engage in infidelity. Men fall into this category more often than women do,

12. COMPONENTS OF INFIDELITY 12
as gender norms encourage the former to be more assertive and autonomous. It is also easier to
carry out infidelity if one is unmarried, as there is not a spouse that one must constantly
circumvent; past studies have also shown, on average, that married persons have a more negative
opinion on infidelity and are thus less likely to engage in the behavior.
Biological factors also correlate heavily with infidelity. It is more evolutionarily
advantageous for a man to engage in infidelity than a woman, as he is able to spread his genes to
multiple partners at one time. Women, however, can only carry the offspring of one partner at a
time and are tasked with nursing and other forms of caregiving, so it is more advantageous for
them to have a partner who will steadily provide them with resources. Therefore, women are
typically less likely to cheat due to the benefits their partners can bring them. Infidelity in
women was typically an adaptive behavior to keep the DNA pool diverse when humans lived in
small units. Today this is not an issue, as genetic relatives live further apart and potential mates
are geographically much closer, which correlates to decreased rates of women engaging in
infidelity, as the adaptation has mostly become obsolete. Thus, women are more likely to cheat
when there is an obvious advantage to the behavior but otherwise tend to avoid it under a
majority of circumstances. Women with more active Vasopressin receptors, however, were
found to exhibit higher percentages of cheating behavior, but it is currently unknown if the
receptor influences the behavior or vice versa (Zietsch et al. 2014).
Men with close oppose-sex friends are more likely to engage in infidelity as well. As
men typically consider this friendship as a gateway into a relationship, they are more willing to
make romantic advances than women who are in a close friendship with men. This infidelity
often comes in the form of mate-poaching, which could theoretically lead to double counts of
infidelity if both man and poached female mate are already in relationships (Pham et al. 2015).

13. COMPONENTS OF INFIDELITY 13
Persons who have been the victims of infidelity, a majority of them women, are less likely to
engage in infidelity themselves. They are also better suited to recognize infidelity and will thus
adjust their behavior to avoid repeating the unfavorable scenario. Women are also more suited to
recognize infidelity because the odds of a woman being a victim of infidelity are greater than of
a man being a victim of infidelity, even if the woman has not been victimized before. Lastly,
women are less likely to partake in infidelity because men are more likely to guard their mate.
With focused attention directed towards them, women have less means to engage in infidelity
without being discovered (Ein-Dor et al. 2015)

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References
Ein-Dor, Tsachi., Perry-Paldi, Adi., Hirschberger, Gilad., Birnbaum, Gurit E., and Deutsch,
Danit. (January 2015).
Coping with mate poaching: gender differences in detection of infidelity-related threats.
Evolution and Human Behavior, 36(1), 17-24. Retrieved from
http://eds.a.ebscohost.com/eds/detail/detail?vid=1&sid=6d064af6-a56c-44e9-9d77-
a270da2805b9%40sessionmgr4004&hid=4111&bdata=JnNpdGU9ZWRzLWxpdmU%3d
#db=edselp&AN=S1090513814001019.
AB: People often aspire for true love and committed romantic relationships. These
relationships, however, are recurrently threatened by partner infidelity. The present
research tested a new infidelity-detection model, the rivalry sensitivity hypothesis, that
posits that women are more sensitive to cues of infidelity than men are, and tend to focus
their attention on potential rivals in their mate's vicinity, whereas men show increased
sensitivity of their own partners. In a series of four studies, we found that women
displayed greater alertness to cues of potential partner unfaithfulness than did men, were
quicker and more accurate in detecting cues of infidelity, but were not better than men in
detecting other threats. Women also focused their attention on potential rivals (other
women), whereas men's attention was specifically directed at monitoring their own
partner's intents. These findings suggest that women and men have developed different
strategies aimed at achieving a similar outcome – mate retention.
Jackman, M. (2014). Understanding the Cheating Heart: What Determines Infidelity Intentions?
Sexuality & Culture, 19(1), 72-84. Retrieved from http://ovidsp.tx.ovid.com/sp-

15. COMPONENTS OF INFIDELITY 15
3.15.1b/ovidweb.cgi?&S=PBGAFPMHPFDDPOHONCKKBEDCMDJMAA00&Comple
te+Reference=S.sh.21%7c4%7c1.
Larsen, L.J. and Buss, D.M. (2014). Personality Psychology: Domains of Knowledge About
Human Nature (5th edition). New York, NY: McGraw-Hill Education.
Pham, M.N., Mogilski, J.K., Shackelford, T.K., and Barbaro, N. (2015) Coalitional mate
retention is correlated positively with friendship quality involving women, but negatively
with male–male friendship quality. Personality and Individual Differences, 79, 87-90.
Retrieved from http://eds.b.ebscohost.com/eds/detail/detail?vid=1&sid=18d25fef-5d90-
45f5-958c-
c7f421bdb097%40sessionmgr115&hid=119&bdata=JnNpdGU9ZWRzLWxpdmU%3d#d
b=edselc&AN=edselc.2-52.0-84922998553.
AB: Friendship solved adaptive problems over human evolutionary history, including
cooperative hunting and alloparenting. Pham, Barbaro, and Shackelford (in press)
investigated another potential function of friendship: the provision of coalitional mate
retention, whereby individuals ask an ally to assist with thwarting their romantic partner’s
infidelity. In the current research, 387 participants (176 women) reported how often they
requested or received coalitional mate retention from a male friend and from a female
friend and reported on the quality of each friendship. The results indicate that the
deployment of coalitional mate retention is positively associated with the quality of
friendships with women (female–female friendships, male–female friendships, female–
male friendships), but negatively associated with the quality of male–male friendships.

16. COMPONENTS OF INFIDELITY 16
Zietsch, B.P., Jern, P., Westberg, L., and Santtila, P. (2014).
Genetic analysis of human extrapair mating: Heritability, between-sex correlation,
andreceptor genes for vasopressin and oxytocin. Evolution and Human Behavior, 36(2),
130-136. Retrieved from
http://eds.b.ebscohost.com/eds/detail/detail?vid=1&sid=54860916-c006-43b9-9aa4-
90503bb6c5b6%40sessionmgr111&hid=126&bdata=JnNpdGU9ZWRzLWxpdmU%3d#
db=edselc&AN=edselc.2-52.0-84922930492.