Living in a Genetic World: How Learning About Interethnic Genetic Similarities and Differences Affects Peace and Conflict

Abstract

Information about the degree of one's genetic overlap with ethnic outgroups has been emphasized in genocides, is frequently learned about through media reporting, and is increasingly being accessed via personal genetic testing services. However, the consequence of learning about whether your own ethnic group is either genetically related to or genetically distinct from a disliked ethnic group remains unknown. Across four experiments, using diverse samples, measures and contexts, we demonstrate that altering perceptions of genetic overlap between groups in conflict-in this case Arabs and Jews-impacts factors that are directly related to interethnic hostility (e.g., aggressive behaviors, support of conflict-related policies). Our findings indicate that learning about the genetic difference between oneself and an ethnic outgroup may contribute to the promotion of violence, whereas learning about the similarities may be a vital step toward fostering peace in some contexts. Possible interventions and implications are discussed.

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Personality and Social
Psychology Bulletin
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DOI: 10.1177/0146167216642196
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Article
“Specialists in human genetics tell us that the small population
of Tutsi is due to the fact that they only marry one another . . . a
cockroach cannot give birth to a butterfly. A cockroach gives
birth to another cockroach.”
—Kangura (March 1993, p. 155, as cited in Eltringham 2006)
“The Abraham Fund—named for the common ancestor of both
Jews and Arabs and dedicated to transforming the landscape of
Jewish–Arab relations in Israel.”
—The Abraham Fund (2014)
As shown in the above quotes, some of the most extreme
efforts to instigate violent conflicts and genocides (e.g.,
Rwandan Genocide, Bosnian Genocide1) have been accom-
panied by rhetoric that emphasizes genetic differences
between ethnic groups. Conversely, in an effort to promote
peace, some conflict reduction programs (e.g., The Abraham
Fund) highlight that ethnic groups actually share genetic
qualities. Meanwhile, the popular media is increasingly
reporting new discoveries on the genetic differences between
ethnic and racial groups, many of who already have a history
of interethnic conflict. For instance, Discover Magazine
recently reported on the genetic differences between the
Tutsi and Hutu,2 the Medical Daily on those between Jews
and Arabs,3 and The Telegraph on those between White-
Europeans and the Roma.4 Moreover, using personal genetic
testing services (e.g., 23andMe, Geno 2.0) to determine one’s
degree of genetic overlap with various ethnic or racial groups
is growing rapidly (Wolinsky, 2006), and over 3 million tests
have now been sold worldwide.5 But, what are the actual
consequences of learning about genetic differences and simi-
larities between ethnic groups who are engaged in conflict?
There is reason to believe that learning about how your
racial or ethnic group is genetically related to, or distinct
from, an enemy group may powerfully influence your atti-
tudes and behaviors toward members of that group. Genetic
information can activate an evolutionary-based preference
for individuals who share the greatest proportion of one’s
642196PSPXXX10.1177/0146167216642196Personality and Social Psychology BulletinKimel et al.
research-article2016
1Harvard University, Cambridge, MA, USA
2University of Michigan, Ann Arbor, USA
3University of Oslo, Norway
4University of Aarhus, Denmark
5Interdisciplinary Center, Herzliya, Israel
Corresponding Author:
Sasha Y. Kimel, Psychology Department, Harvard University, 33 Kirkland
Street, Cambridge, MA 02138, USA.
Email: skimel@fas.harvard.edu
Living in a Genetic World: How Learning
About Interethnic Genetic Similarities
and Differences Affects Peace and Conflict
Sasha Y. Kimel1, Rowell Huesmann2, Jonas R. Kunst1,3,4,
and Eran Halperin5
Abstract
Information about the degree of one’s genetic overlap with ethnic outgroups has been emphasized in genocides, is frequently
learned about through media reporting, and is increasingly being accessed via personal genetic testing services. However,
the consequence of learning about whether your own ethnic group is either genetically related to or genetically distinct
from a disliked ethnic group remains unknown. Across four experiments, using diverse samples, measures and contexts, we
demonstrate that altering perceptions of genetic overlap between groups in conflict—in this case Arabs and Jews—impacts
factors that are directly related to interethnic hostility (e.g., aggressive behaviors, support of conflict-related policies). Our
findings indicate that learning about the genetic difference between oneself and an ethnic outgroup may contribute to the
promotion of violence, whereas learning about the similarities may be a vital step toward fostering peace in some contexts.
Possible interventions and implications are discussed.
Keywords
essentialism, genetics, conflict, culture/ethnicity, genocide
Received August 19, 2015; revision accepted February 28, 2016
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2 Personality and Social Psychology Bulletin
genes (Colman, Browning, & Pulford, 2012). Just like earlier
historical emphases on “blood” and “spirits,” it can also trig-
ger folk psychological notions about racial and ethnic groups’
immutable, underlying nature (Gelman, 2003). Possibly
more so than other scientific (Dar-Nimrod & Heine, 2011) or
biological information (Shiloh, Rashuk-Rosenthal, &
Benyamini, 2002), this “genetic essentialist” way of thinking
can make groups appear deeply distinctive from each other
(Dar-Nimrod & Heine, 2011). Indeed, research shows that
emphasizing low (vs. high) genetic overlap within the global
human population may lead people to evaluate ingroup and
outgroup faces in a more dichotomous way (Plaks, Malahy,
Sedlins, & Shoda, 2012), while priming people with the
alleged genetic underpinnings of racial and ethnic categories
can increase factors associated with stereotyping and preju-
dice (Keller, 2005; No et al., 2008; Williams & Eberhardt,
2008). Yet, despite theorizing that thinking about the genetic
basis of racial or ethnic dissimilarities may lead to some of
the most severe forms of interethnic hostility (Yzerbyt, Judd,
& Corneille, 2004), the consequences remain vastly
unknown. For instance, previous work has not yet systemati-
cally examined the consequences of emphasizing genetic
differences and similarities between groups, nor has it exam-
ined its impact within a context of conflict. Finally, how
intergroup conflict is affected by genetic information, more
broadly, as well as by any kind of essence placeholder also
remains missing.
It is well known that drawing ones’ attention to group dif-
ferences tends to increase processes associated with group
antipathy (Tajfel & Turner, 1979), whereas bringing aware-
ness to intergroup similarities can sometimes attenuate these
effects (see Gaertner, Mann, Dovidio, Murrell, & Pomare,
1990). Given peoples’ limited understanding of genetics
(Lanie et al., 2004), the widespread belief that genes provide
hard evidence of causation (Cheung & Heine, 2015; Haslam,
2011), and that they can both activate an evolutionary-based
preference for genetic kin (Colman et al., 2012) and make
groups appear deeply distinctive from each other (Dar-
Nimrod & Heine, 2006), it is likely that genetic information
may indeed be powerful in both exacerbating and mitigating
ethnic conflict. Importantly though, not all commonality-
based interventions have been found to be effective and many
attempts have actually increased bias by threatening groups’
desire to maintain their distinctness from an enemy group
(Crisp, Walsh, & Hewstone, 2006; Gaertner, Mann, Murrell,
& Dovidio, 1989; Hewstone & Brown, 1986; Hornsey &
Hogg, 2000; Wenzel, Mummendey, & Waldzus, 2007). Yet,
because genes evoke views of essences that are perceived to
be “underlying, deep and unobserved” (Dar-Nimrod & Heine,
2011), genetic similarities may actually lead to the desired
decrease in conflict by uniting groups in a way that still allows
for differentiation on observable characteristics (e.g., cul-
ture). Using the context of Jewish–Arab intergroup relations,
here, we test the impact of emphasizing genetic similarities
and differences between groups in conflict.
One of the most entrenched and consequential conflicts of the
last 50 years is the conflict between Jews and Arabs in the Middle
East. While the Arab and Jewish people continue to engage in an
ongoing pattern of intractable violent conflict, research has only
recently begun exploring their degree of genetic relatedness,
resulting in conflicting perspectives. Whereas some studies
claim considerable genetic overlap between Jews and Arabs liv-
ing in the Middle East as well as in the diaspora communities
(Hammer et al., 2000), others argue that these groups are geneti-
cally distinct (Costa et al., 2013). Regardless of which is most
accurate, framing this information in terms of considerable
genetic similarities or differences may critically impact these
groups’ level of hostility toward one another.
To explore this, we ran four experimental studies. First, we
examine whether giving Jews and Arabs information about
either their substantial genetic similarities or differences
impacts their degree of explicit and implicit antipathy toward
each other (Study 1). Next, we test whether these effects go
beyond mere attitudinal bias and also affect Jews’ actual physi-
cal aggression toward an Arab individual during a competitive
task (Study 2). Taking the paradigm to the Israeli–Palestinian
conflict and outside a controlled laboratory, we then examine
the impact on attitudes toward more abstract war-related poli-
cies among American Jews recruited online (Study 3). Last, we
replicate our experimental paradigm in a field study with
Jewish participants in Israel—a context high in violent conflict
(Study 4). Across the studies, we predict that learning about
genetic differences will exacerbate processes directly related to
sustaining intergroup hostility, while learning about genetic
similarities will help mitigate these effects.
Study 1
Method
Participants. A total of 123 Jewish and 57 Arab participants
(Mage = 18.71, SDage = 1.00; 52.2% females) were recruited
via subject pool prescreening procedures at University of
Michigan’s Ann Arbor and Dearborn campuses. Participants
received course credits for taking part in the study.
Procedure. To reduce demand characteristics that might
induce participants to change their behaviors according to
the assumed purpose of this experiment, participants were
recruited in such a way that no one was aware that they were
selected because of their ethnicity. In addition, the paradigm
was masked as a “Memory and Distraction” study. This pro-
cedure was followed in each study presented in this article.
Specifically, participants were informed that they would
complete various tasks intended to disrupt their memory for
the content of our manipulation (i.e., the article), before tak-
ing a memory test at the end. This included filler tasks that
were explicitly chosen to bolster the cover story (e.g., search-
ing for article-relevant words and rating attitudes about
article-related content; see online appendix for all filler
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Kimel et al. 3
tasks). Crucially, our actual dependent variables were embed-
ded within these fillers as “distraction tasks.”
Participants were first randomly assigned to read and
memorize one of two ostensible BBC News articles (adapted
from an actual BBC article which reported on genetic simi-
larities between Jews and Arabs): “Jews and Arabs are
‘genetic brothers’” (i.e., genetic siblings condition) or “Jews
and Arabs are not ‘genetic brothers’” (i.e., genetic strangers
condition). These articles were one page, carefully matched
in terms of length and language complexity, and reported
new research published in a highly ranked scientific journal
that found either striking similarities or differences between
both groups’ DNA (see online appendix for the articles).
After reading the article, participants completed the vari-
ous “distraction tasks” which included measures of implicit
and explicit outgroup antipathy toward Arabs and Jews. At
the end, they completed a “memory test” in which they
recalled up to 10 aspects of the article. This test was intended
to check whether they were paying attention to its content
and, hence, would allow us to exclude participants who were
inattentive to the main focus of the article. Before being
probed for suspicion regarding the true purpose of the study6
and being debriefed, participants completed a manipulation
check and a demographics questionnaire.
Measures
Perceived genetic similarity. As a check that we had indeed
manipulated perceptions of genetic relatedness (i.e., the
manipulation check), participants rated how much they
agreed with the statement “Jews and Arabs are genetically
similar” on a 7-point Likert scale (1 = strongly disagree, 7 =
strongly agree).
Explicit outgroup antipathy. Participants rated “typical”
Arab- and Jewish Americans on four-bipolar dimensions
(i.e., Peaceful–Violent, Friendly–Unfriendly, Nice–Mean,
Helpful–Unhelpful) using an 8-point scale (Bar-Tal & Labin,
2001). Moreover, to test whether our manipulation would
solely affect attitudes toward genetically related groups or,
instead, elicit positivity toward outgroups more generally,
participants also rated African Americans on the same scale.
In line with previous research (Castano, Yzerbyt, Paladino, &
Sacchi, 2002), difference scores were created by subtracting
ingroup ratings from outgroup ratings. Based on these scores,
mean scores for antipathy toward Jewish and Arab Americans
(α = .81) and African Americans were computed (α = .70).
Implicit outgroup antipathy. An Implicit Association Test
(Greenwald, Nosek, & Banaji, 2003), consisting of Arab and
Jewish names, paired with pleasant and unpleasant catego-
ries was used (Huesmann, Dubow, Boxer, Souweidane, &
Ginges, 2012). Consistent with common scoring procedures
(Greenwald et al., 2003), upper-bound and lower-bound
outliers were removed and an error penalty for incorrect
responses was given when creating the D-score.
Results
Confirming the effectiveness of our manipulation, a 2
(Condition: Genetic strangers vs. Genetic siblings) by 2
(Ethnicity: Arab vs. Jewish) analysis of variance (ANOVA)
showed that participants generally perceived more genetic
similarity between Jews and Arabs in the genetic siblings
condition (M = 5.17, SE = .17) than in the genetic strangers
condition, (M = 3.17, SE = .18; ΔM = 1.96, 95% confidence
interval [CI] [1.47, 2.45]), F(1, 175) = 62.36, p < .001, ηp
2 =
.26. The interaction between ethnicity and condition remained
insignificant, F(1, 175) = .20, p = .654, indicating that the
manipulation had invariant effects in both ethnic groups.
When it came to the test of our hypothesis, participants in
the genetic siblings condition showed less explicit antipathy
toward their respective genetically similar outgroup (M =
.95, SE = .16) compared with those in the genetic strangers
condition, as expected (M = 1.39, SE = .18; ΔM = −.51, 95%
CI [−.98, −04]), F(1, 176) = 4.66, p = .032, ηp
2 = .03, see
Figure 1. Again, this effect did not interact with participants’
ethnicity, F(1, 175) = .73, p = .393. No effects were observed
for explicit antipathy toward African Americans, a group that
was not mentioned as genetic siblings or strangers in the
manipulation, F(1, 168) = .06, p = .809, and for implicit
antipathy (i.e., the D-score), F(1, 169) = .56, p = .457.
Preliminary Discussion
This first study provided initial evidence that heightening
Arabs’ and Jews’ awareness of their genetic similarities and
differences impacts their explicit antipathy toward one another.
As expected, attitudes toward African Americans were unal-
tered, suggesting that our manipulation did not influence
antipathy levels toward genetically distant ethnic groups.
Implicit antipathy was also unaffected, which may be due to
the difficulties of changing peoples’ automatic attitudes
(Crandall & Eshleman, 2003) and the very weak relationship
between implicit measures and explicit attitudes generally
(Oswald, Mitchell, Blanton, Jaccard, & Tetlock, 2013).
While the present study provides initial support for our
predictions, it is limited as it only tested effects on attitudinal
bias. Given that the Jewish–Arab conflict is characterized by
high levels of interethnic aggression between group mem-
bers, it is crucial to test whether experimental effects can also
be observed on behavioral bias. We addressed this question
in the next study.
Study 2
Method
Participants. To facilitate recruitment, and since no differ-
ences were observed between Arabs and Jews in the first
study, we focused on Jewish participants here. A total of 131
participants were recruited through the same procedure as in
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4 Personality and Social Psychology Bulletin
Study 1. After excluding 16 participants who incorrectly
answered the “critical question” about the article’s content
and, hence, failed to pay attention to the manipulation (see
the new memory test described below) as well as two extreme
outliers who had z-scores exceeding the ±3 SD cutoff in the
Competitive Reaction Time (CRT) noise blast task (see
Anderson & Carnagey, 2009 for similar procedures), the
final study sample comprised 113 participants (Mage = 19.43,
SDage = .89, 54.1% females).
Procedure. The procedure was identical to Study 1 with the
exception that the CRT noise blast task—a reliable, valid,
and well-established measure of behavioral aggression (see
Anderson & Dill, 2000)—constituted our dependent mea-
sure. As in the previous study, this task was again disguised
as a “distraction task” amidst filler tasks. Here, participants
were led to believe that they would be competing with a ran-
domly chosen opponent who happened to have “Moham-
med” as his/her last name. To keep gender constant, the
alleged opponent had the same gender as the participant. A
pretest had shown that participants perceived both the oppo-
nent to be real and his/her last name to be of Arabic origin in
this experimental set-up.
After the alleged random opponent assignment, partici-
pants were told that they and their purported opponent would
press a button as fast as they could on each of nine trials and
that whoever was slower would receive loud blasts of noise
from the winner. Crucially, participants set the level of noise
that their opponent would receive, from 60 dB (Level 1) to
105 dB (Level 10, about the same volume as a fire alarm) in
advance of each trial. A nonaggressive no-noise option
(Level 0) was also provided. Moreover, participants could
also control how long their opponent suffered by setting the
noise duration from 0 to 2.5 s.
In the first trial, when the participant sets the intensity and
duration, they have no information yet about what levels
their opponent will set for them. However, after the first trial,
participants become aware of their opponents’ aggressive
tendencies and their response patterns mirror their oppo-
nent’s behavior (Bremner, Koole, & Bushman, 2011). Thus,
in line with previous studies (Bremner et al., 2011), we were
interested in the baseline aggression in Trial 1, where partici-
pants have received no noise from their opponent yet and,
therefore, have not been provoked to respond in a particular
manner. However, to bolster the cover story that this was
merely a distracting reaction-time task, participants com-
pleted all nine trials.
As in Study 1, participants were given a memory test at the
end. In this study and all remaining studies, it included a five-
question multiple-choice test that included a “critical ques-
tion” about the main findings reported in the article (i.e., “The
study found that the Jewish and Arab populations share [very
few/a common set of] . . . a. genetic factors; b. biological fac-
tors; c. cultural factors”). Finally, before being debriefed, they
completed the manipulation check from Study 1 and a demo-
graphic questionnaire.
Results
Supporting the effectiveness of our manipulation, partici-
pants in the genetic siblings condition perceived more
genetic similarity (M = 4.95, SE = .20) between Arabs and
Jews than those in the genetic strangers condition (M = 4.08,
SE = .20; ΔM = .87, 95% CI [.32, 1.43]), F(1, 111) = 9.74,
p = .002, ηp
2 = .08.
A significant effect of the experimental condition was
also observed on the intensity of punishment given to the
outgroup opponent: Jewish participants in the genetic sib-
lings condition punished their alleged Arab opponent with
less intense noise blasts (M = 3.61, SE = .28) than those in the
genetic strangers condition, (M = 4.50, SE = .30; ΔM = −.87,
95% CI [−1.69, −.06]), F(1, 111) = 4.50, p = .036, ηp
2 = .04,
see Figure 2. Length of the noise blasts given to the opponent
was not affected, p = .648, which may be due to high levels
of participant error and confusion when varying the noise
duration, as observed in earlier research (see Anderson &
Dill, 2000).
Preliminary Discussion
Using a behavioral measure, Study 2 demonstrated that aware-
ness of interethnic genetic similarities and differences also
impacts actual physical aggression between members of
groups in conflict, with aggression being lower when similari-
ties are emphasized than when differences are emphasized.
Although our first two studies indicated that genetic informa-
tion may indeed alter intergroup attitudes and behavior, they
give no information about whether it is awareness of genetic
similarities that leads to less bias or whether it is awareness of
differences that leads to more bias. To examine this, we
included a plain control condition in the next study. We also
Figure 1. Participants in the genetic siblings (vs. strangers)
condition show significantly less explicit bias toward the
genetically similar outgroup in Study 1.
Note. Error bars represent standard errors.
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Kimel et al. 5
examine our paradigm’s ecological validity by testing whether
our manipulation would impact more abstract political atti-
tudes about a relevant, real-life interethnic conflict scenario
(i.e., the Israel–Palestine conflict), among a more representa-
tive Jewish sample that was tested outside the laboratory.
Moreover, we test whether the impact on attitudinal group
antipathy observed in Study 1 may underlie and, hence, medi-
ate experimental effects on political attitudes as it did in simi-
lar research (Kunst, Thomsen, Sam, & Berry, 2015).
Study 3
Method
Participants. Two hundred and twenty-two Jewish partici-
pants were recruited via various listservs from Jewish com-
munities across the United States. In exchange for
participating in this online study, respondents could enter
into a lottery for a $100 Amazon gift card. Eleven partici-
pants were discarded due to failing to pay attention to the
manipulation as indicated by incorrect answers to the “criti-
cal question” (described in Study 2). Because the study was
run online where attention is particularly likely to wax and
wane, it was critical to use an additional check to measure
how attentive participants were throughout the study (Mani-
aci & Rogge, 2014). Thus, to assess this, we used partici-
pants’ rating of how well they remembered “the details of the
article, right now” (1 = not at all, 12 = completely). A total of
189 participants (Mage = 24.33, SDage = 8.86; 59.3% females)
were retained for analyses, as they scored on or above the
midpoint (> 6) on this composite measure (i.e., attention
across four time points, α = .96) and, hence, paid sufficient
attention throughout the study.
Procedure. The procedure was similar to the previous stud-
ies, except that the study was run online and a new neutral
BBC News article was added (i.e., “New BBC channels get
launch dates”; see online appendix) to provide a plain control
condition. After reading the article, participants answered the
usual filler questions, the explicit outgroup antipathy mea-
sure from Study 1 (α = .93), and a measure of the extent to
which Israel should pursue diplomatic negotiations with the
Palestinians (i.e., Support for Peacemaking). The study
ended with the manipulation check, memory test, demo-
graphics, and debriefing.
Measures
Support for peacemaking. Support for peacemaking was
assessed using an adapted nine-item measure developed by
Vail and Motyl (2010). In our version, Jewish participants
rated the extent to which Israel should pursue diplomatic
negotiations with the Palestinians (e.g., “In order to achieve its
goals, Israel should pursue peaceful diplomacy with the Pal-
estinians instead of using aggressive actions”) on a 10-point
scale (1 = strongly disagree, 10 = strongly agree; α = .91).
Results
An ANOVA showed a main effect of condition on the manipu-
lation check, F(2, 185) = 56.35 p < .001, ηp
2 = .38. Participants
in the genetic siblings condition perceived the most genetic
similarities between Jews and Arabs (M = 5.96, SE = .18), fol-
lowed by participants in the control (M = 5.41, SE = .20) and
the genetic strangers condition (M = 3.32, SE = .19). Simple
contrasts revealed that all groups differed significantly from
each other at ps < .001—.043 (similarity vs. control: ΔM = .54,
95% CI [.02, 1.07]; difference vs. control: ΔM = 2.10, 95%
CI [1.56, 2.62]; similarity vs. difference: ΔM = 2.64, 95% CI
[2.12, 3.15]).
The main effect of experimental condition on antipathy
toward Arabs was marginally significant, F(2, 186) = 2.67,
p = .072, ηp
2 = .03. Replicating the effects of Study 1, simple
Figure 2. In the CRT noise blast task from Study 2 (Trial 1), participants in the genetic siblings (vs. strangers) condition punished the
Arab opponent with less aggression.
Note. CRT = Competitive Reaction Time.
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6 Personality and Social Psychology Bulletin
contrasts revealed that participants in the genetic siblings
condition had less antipathy toward Arabs (M = .37, SE =
.17) than participants in the genetic strangers condition (M =
.94, SE = .18; simple contrast: p = .022, ΔM = −.57, 95% CI
[−1.06, −.08]). Although the strength of antipathy of partici-
pants in the control condition fell in between these means
(M = .63, SE = .18), it did not differ compared with the sib-
lings (p = .291) or strangers condition (p = .235).
Also, the main effect of experimental condition on sup-
port for peacemaking was marginally significant, F(2, 186) =
2.54, p = .082, ηp
2 = .03) and simple contrasts revealed that
participants in the genetic siblings condition showed signifi-
cantly more support for peacemaking (M = 6.72, SE = .23)
than those in the strangers (M = 6.09, SE = .24; p = .054, ΔM
= .64, 95% CI [−.01, 1.28]) and control conditions (M = 6.08,
SE = .24; p = .055, ΔM = .64, 95% CI [−.01, 1.30]). The con-
trol and strangers condition did not differ significantly from
each other (p = .977).
As it was the genetic strangers and siblings conditions
that differed significantly for antipathy as well as for sup-
port for peacemaking, we used the standard regression
approach to test a mediational model with an experimental
dummy variable as predictor (0 = genetic strangers condi-
tion, 1 = genetic siblings condition), outgroup antipathy as
mediator, and support for peacemaking as the dependent
variable. While the experimental design did not allow us
establish the causal direction between the mediator (e.g.,
outgroup antipathy) and dependent variables (e.g., support
for peacemaking), this order was chosen based on previous
research showing downstream effects of attitudinal bias on
policy support (Kunst et al., 2015) and also followed the
presentation order in the survey. To start with, the experi-
mental condition predicted more support for peacemaking to
marginally significant extent (β = .15, p = .086), F(1, 123) =
3.00, p = .086, as well as significantly lower values on the
mediator outgroup antipathy toward Arabs (β = −.19, p =
.037), F(1, 123) = 4.45, p = .037. In the final mediation
model, F(2, 122) = 12.56, p < .001, antipathy emerged as
the only significant predictor of support for peacemaking
and, hence, fully mediated the experimental effects (see
Figure 3). Bootstrapping with 5,000 random resamples
showed that the resulting indirect effect, going through
antipathy toward Arabs, was significant (B = .27, 95% CI
[.02, .60]).
Preliminary Discussion
Results showed that heightening awareness about intereth-
nic genetic similarities versus differences can also impact
war-sustaining political views about a relevant conflict, in
this case, the one between Israel and Palestine. Moreover,
compared with both the genetic strangers condition and the
baseline control conditions, emphasizing genetic similari-
ties was related to more support for peacemaking, high-
lighting its potential to mitigate conflicts. When comparing
the genetic strangers and siblings condition, our mediation
model suggested that the marginally higher support for
peacemaking in the genetic similarities condition was due
to lower levels of explicit outgroup antipathy. Although the
causal relationship between the mediator and dependent
variable cannot be established with certainty, this suggests
that our manipulation primarily affects more direct forms
of bias, with downstream effects on more abstract political
attitudes.
So far, the three first studies have provided evidence of
the broad range of effects in a U.S. context. In the next and
last study, we wanted to answer the question of whether
our paradigm could also have an impact in a context that is
characterized by protracted interethnic violence and deeply
entrenched negative attitudes. To address this, we con-
ducted a field experiment in Israel. Furthermore, previous
research suggests that increasing constructive emotions
about intractable conflicts, including hope, is critically
related to their resolution (Cohen-Chen, Halperin, Porat, &
Bar-Tal, 2014). Hence, we also examine the impact on a set
of such emotions and expect them, similar to negative out-
group bias in Study 3, to mediate effects on political
attitudes.
Figure 3. A reduction of outgroup bias mediates the marginal experimental effect on support for peacemaking.
Note. Estimate in parentheses represents coefficient after the mediator was added to the model.
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Kimel et al. 7
Study 4
Method
Participants. One hundred and eighty-four Jewish Israelis
were recruited and participated in our paper-and-pencil study
on commuter trains from Tel Aviv to BeerSheva and Haifa
(Northern and Southern Israel, respectively) in exchange for
several chocolates. Seven participants were discarded due to
failing to pay attention to the manipulation as indicated by
incorrect answers to the “critical question.” Because of the
highly uncontrolled and noisy environment, adding an addi-
tional attention check at the beginning of the study was cru-
cial to both motivate participants to read the article’s content
as well as to screen out participants who did not. Thus, at the
bottom of the article, we included two fill-in-the-blank sen-
tences taken from the main content of the article. If partici-
pants were uncertain about how to answer these basic
questions, glancing at the article again would provide them
with these answers and thus indicate that they were indeed
paying attention to the content of the article. Possibly due to
the highly noisy setting in which, despite our request to limit
outside distractions, participants were often listening to
music, making phone calls, texting, or interacting with other
passengers, only 93 participants (Mage = 28.82, SDage = 12.46;
53.8% females) showed that they were paying attention to
the article’s content by accurately completing these simple
questions and, hence, were retained for analyses (see Thomas
& Clifford, 2016 and Berinsky, Huber, & Lenz, 2012 for
comparable rates in other non-laboratory contexts).
Procedure. Analogous to Study 3, participants were randomly
assigned to read one of three news articles. However, while
the articles were the same in content, this time they appeared
to be published in Ynet (a branch of Yedioth Ahronot—Isra-
el’s second leading daily newspaper), rather than in the BBC.
These and all other materials were forward-back translated
into Hebrew by bilinguals.
Along with the filler distraction tasks, we assessed sup-
port for concrete political compromises that Israel might
make to achieve peace with the Palestinians (i.e., Support for
Political Compromise scale), support for Israel’s political
exclusion of its Palestinian citizens (i.e., Political Exclusion
scale), support for Israel’s harm of Palestinians to achieve its
military goals (i.e., Collective Punishment scale), hope about
the Israeli–Palestinian conflict (i.e., Hope scale), and other
emotions that are generally associated with either having a
destructive or constructive effect on the resolution of conflict
(i.e., Positive and Negative Emotional Outgroup Sentiments
scale).7
Measures
Positive and negative emotional outgroup sentiments. On a
6-point scale (1 = not at all, 6 = to a very large extent), we
measured the extent to which participants felt seven emotions
toward Palestinians. These emotions have been found to have
distinct effects on conflict attitudes (Halperin, Sharvit, &
Gross, 2011). However, since factor analyses indicated a clear
two-factor solution, we computed a scale for emotions that
generally have a destructive effect on conflict (i.e., hatred,
fear, irritation, hostility; α = .80) and a second scale for those
that generally have a more constructive effect (i.e., optimism,
shame, guilt; α = .77; Halperin et al., 2011).
Hope about the conflict. Hope about the Israeli–Palestinian
conflict was measured with 14-items adapted from Cohen-
Chen et al. (2014) such as “I am hopeful regarding the solu-
tion of the Israeli–Palestinian conflict” (α = .86). Responses
were rated on a 6-point scale (1 = not at all, 6 = to a very
large extent).
Support for political compromises. In contrast to the more
general Support for Peacemaking measure from Study 3,
we assessed support for concrete political compromises that
Israel might make to achieve peace with the Palestinians
(i.e., a two-state solution; stopping settlement building; mak-
ing concession about the status of Jerusalem; establishing
economic relations between Israel and the Palestinian terri-
tories) using Halperin et al.’s (2011) four-item measure (α =
.80). Responses were rated on a 6-point scale (1 = strongly
oppose, 6 = strongly support).
Political exclusion. The degree to which participants sup-
ported the political exclusion of Palestinian citizens of Israel
was assessed with a five-items measure (e.g., “The right of
Palestinian citizens of Israel to vote in Israeli elections should
be revoked”; α = .93) adapted from Halperin, Canetti-Nisim,
and Hirsch-Hoefler (2009) which was rated on a 6-point
scale (1 = strongly oppose, 6 = strongly support).
Collective punishment. Willingness to harm Palestinians to
achieve Israel’s military goals (e.g., “If thousands of Pales-
tinians were to start marching toward Jerusalem, the Israel
Defense Forces should use firearms to stop them, even at
the cost of tens of fatalities and hundreds of wounded”) was
assessed using an adapted three-item measure (Reifen Tagar,
Morgan, Halperin, & Skitka, 2014; α = .66). Responses were
rated on a 6-point scale (1 = strongly oppose, 6 = strongly
support).
Results
As in the previous studies, the manipulation check differed
significantly between the conditions, F(2, 87) = 4.02, p =
.021, ηp
2 = .08. Participants in the genetic strangers condition
(M = 3.55, SE = .27) perceived a significantly lower degree of
overlap than participants in the control (M = 4.85, SE = .37;
simple contrast: p = .011, ΔM = 1.30, 95% CI [.31, 2.30]) and
genetic siblings condition (M = 4.67, SE = .27; simple con-
trast: p = .016, ΔM = −1.12, 95% CI [−2.03, −.22]). The
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8 Personality and Social Psychology Bulletin
genetic siblings and control condition did not differ from
each other (simple contrast: p = .678), possibly indicating
that the similarity condition can be seen as the social default
for participants in this context. Consistent with similar stud-
ies (Kunst et al., 2015), the control and sibling condition
were, therefore, pooled and compared against the genetic
strangers condition in further analyses.
In a multivariate analysis of variance (MANOVA) with
all dependent variables, the experimental dummy variable (0
= control and genetic siblings, 1 = genetic strangers) showed
a significant multivariate effect, F(5, 85) = 2.88, p = .013,
ηp
2 = .17. Between-subject effects showed that the experi-
mental condition had a significant effect on support for polit-
ical compromises (ΔM = .88, 95% CI [.26, 1.50]), F(1, 90) =
8.01, p = .006, ηp
2 = .08; support for political exclusion (ΔM =
−.96, 95% CI [−1.59, −.34]), F(1, 90) = 9.54, p = .003, ηp
2 =
.10; support for collective punishment (ΔM = −.81, 95% CI
[−1.48, −.14]), F(1, 90) = 5.69, p = .019, ηp
2 = .06; hope
about the conflict (ΔM = .43, 95% CI [.06, .81]), F(1, 90) =
5.22, p = .025, ηp
2 = .06; and on emotions that generally have
constructive effect on conflict resolution (ΔM = .88, 95% CI
[.30, 1.45]), F(1, 90) = 9.26, p = .003, ηp
2 = .09. Emotions
that tend to have a destructive effect were unaffected (p =
.335). Specifically, participants in the genetic stranger condi-
tions showed less support for political compromise and lower
hope and other emotions that have constructive effects on
conflict, while showing more support for collective punish-
ment toward Palestinians and more support for the political
exclusion of Palestinian citizens of Israel (see Figure 4).
To replicate and further explore the mediation finding
from the previous study, we next tested whether a reduction
in hope about the conflict and in other emotions that gener-
ally have constructive effects on conflict resolution would
mediate the effect of the experimental condition on support
for political exclusion, political compromise, and collective
punishment. Consistent with the MANOVA results, regres-
sion models showed that emphasizing genetic differences
(vs. similarities and control) led to less support of a political
compromise (β = −.30, p = .003), F(1, 91) = 9.07, p = .003;
more support for political exclusion (β = .31, p = .003), F(1,
91) = 9.54, p = .003; and more support for collective punish-
ment (β = .24, p = .019), F(1, 90) = 5.69, p = .019. Moreover,
it led to lower scores on the mediators constructive emotions
toward Palestinians (β = −.30, p = .003), F(1, 91) = 9.07, p =
.003, and hope about the conflict (β = −.23, p = .025), F(1,
91) = 5.18, p = .025. In the final models, support for political
compromise, F(3, 89) = 24.67, p < .001; support of political
exclusion, F(3, 88) = 20.54, p < .001; support for collective
punishment, F(3, 88) = 9.85, p < .001, that included both
predictors and mediators as independent variables, construc-
tive emotions fully mediated the experimental effects on sup-
port for compromise and support of collective punishment,
while both constructive emotions and hope fully mediated
the effects on support of political exclusion (see Figure 5).
Bootstrapping showed that the indirect effect on support of
political compromise was significant and negative (B = −.54,
95% CI [−.95, −.22]), whereas the effect on collective
punishment was significant and positive (B = .38, 95%
Figure 4. In Study 4, Jewish Israelis in the genetic strangers condition show less positive attitudes about the conflict (i.e., less
support for political compromise; more support for the political exclusion of Palestinian citizens of Israel; more support for collective
punishment) and less constructive emotions related to the conflict (i.e., hope and positive emotions toward Arabs/Palestinians).
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Kimel et al. 9
CI [.10, .83]). In the model with support of political exclu-
sion as dependent variable, both the indirect effect going
through constructive emotions (B = .34, 95% CI [.12, .67])
and the effect going through hope were positive and signifi-
cant (B = .25, 95% CI [.03, .57]).
Preliminary Discussion
Results from this experimental field study in Israel indicated
that emphasizing genetic differences may exacerbate hostil-
ity in a context of unrelenting violent conflict. Relative to
both the genetic siblings and plain control conditions, genetic
differences led Jewish Israeli’s to increase their opposition to
concrete compromises and policies that are critical to the
resolution of conflict, with a decrease in hope and other con-
structive emotions underlying theses effects. Given the con-
text of protracted war, Jewish Israelis may be particularly
less ready than Jewish Americans to learn about interethnic
similarities or, alternatively, genetic similarities between
Jews and Arabs may be the default assumption in this
context.
General Discussion
Only recently has an understanding of the predictive power
of a human’s genetic make-up entered the public conscious-
ness (Nelkin, 2001). Within this time, several genocides have
already used rhetoric about genetic differences to instigate
Figure 5. (a) The effect of the genetic strangers condition on support for political compromise was fully mediated by a decrease in
constructive emotions, while (b) the effect on support for political exclusion of Palestinian citizens of Israel was fully mediated by a
decrease in constructive emotions and hope about the Israeli–Palestinian conflict, and (c) The effect of the genetic strangers condition on
support for collective punishment was fully mediated by a decrease in constructive emotions.
Note. Values in parenthesis represent estimates after the mediator(s) was added to the model.
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10 Personality and Social Psychology Bulletin
violence (e.g., Rwandan Genocide, Bosnian Genocide).
Moreover, people are increasingly seeking personal DNA
testing services to determine their unique ethnic lineages
(Wolinsky, 2006), and the media frequently reports on the
degree of genetic overlap between various ethnic groups
with a history of conflict.
Using Arabs and Jews from diverse samples and contexts,
we demonstrated that those who learn that their ethnic group
is genetically related to an enemy group showed more con-
structive intergroup attitudes, interindividual behaviors, and
support for peaceful policies than those who learn about the
genetic differences. Specifically, in our three studies con-
ducted in the United States, we found that heightening per-
ceptions of interethnic genetic similarities versus differences
altered Jews’ and Arabs’ negative attitudes, and even the real
physical aggression of Jews toward an alleged Arab individ-
ual. In fact, it led to more support for conciliatory policies
among Jews—in this case related to the Israeli–Palestinian
conflict—and, compared with a plain control condition, pro-
vided some evidence that emphasizing genetic similarities
may be one way to help attenuate intergroup conflict. While
previous research has largely focused on how genetic infor-
mation can be used to divide us, this is one of the first studies
to suggest that genetic information can be used to bring us
together (Dar-Nimrod & Heine, 2011). Importantly too,
emphasizing genetic similarities may be fostering a “deep”
unity that still allows for the expression of differences in per-
ceptible domains (e.g., cultural). Thus, this approach may
also be circumventing the limitations of commonality-based
approaches which increase bias by creating a degree of over-
lap that threatens groups’ desire to maintain their distinctive-
ness (Crisp et al., 2006; Gaertner et al., 1989; Hewstone &
Brown, 1986; Hornsey & Hogg, 2000; Wenzel et al., 2007).
However, our field study conducted in Israel painted a
more pessimistic picture. Here, emphasizing genetic differ-
ences exacerbated Jews’ conflict-sustaining attitudes and
emotions, suggesting that learning about how you are geneti-
cally different from an enemy group may have a particularly
menacing effect in contexts of war. Despite these cultural
differences, the process underlying the effects on political
attitudes seemed to be similar. Both in the United States and
in Israel, a change in direct forms of bias (i.e., attitudinal and
emotional) appears to explain why learning about genetic
differences or similarities altered more abstract political atti-
tudes. Yet, a question that remains is: what is the fundamen-
tal process underlying this relationship? We suspect that
altering perceived intergroup genetic overlap may be partic-
ularly powerful in both exacerbating and mitigating ethnic
conflict because it shifts “essentialist views” of these groups
or beliefs in their fixed, core nature (Gelman, 2003). Future
research should explore this by including a measure of essen-
tialism (see Keller, 2005) and by looking at how altering
overlap on genes may be distinct from recent successful
alterations of intergroup commonalities on non-genetic fac-
tors such as religion (Kunst & Thomsen, 2015), nationality
(Banfield & Dovidio, 2013), shared victimhood (Shnabel,
Halabi, & Noor, 2013), or emotions (McDonald et al., 2015).
The present research can be seen as providing the first
systematic investigation of the consequences of emphasizing
genetic differences and similarities between groups as well
as of its impact within a context of conflict. Importantly, this
research also gives insight into how intergroup conflict is
affected by both genetic information, more broadly, as well
as by essence placeholders. Across four studies, we obtained
support for the general pattern of our results. Moreover,
using cross-cultural and cross-national samples, diverse
methods, and a variety of measures of intergroup aggression
(e.g., Noise Blast Task, collective punishment), we provided
evidence for the broad validity and robustness of our effects.
Yet, one limitation of our work is that we included a plain
control condition in only half of our studies, leaving some
uncertainty about the relative impact of emphasizing genetic
differences versus similarities. Indeed, while our study con-
ducted in the United States suggested that information about
genetic similarities may reduce intergroup tensions (Study
3), it was the genetic difference condition that led to more
bias in Israel (Study 4). Hence, it is possible that increasing
awareness about intergroup genetic similarities may reduce
tensions only in less severe conflict scenarios, while high-
lighting genetic differences may be especially detrimental in
high-conflict contexts, such as the Middle East. Given that
rhetoric emphasizing genetic differences between groups
does occur in conflict-discourse, this finding is particularly
alarming.
An important topic of future research is to investigate
whether and under which conditions status and power inter-
act with the effects we observed. While we did not observe
different effects between Jewish and Arab participants in the
U.S. context, we included an Arab sample in one of our stud-
ies only. By more consistently including participants from
both high- and low-status groups, future research should
explore the potential and limitations of prejudice reduction
effects within such asymmetries (Banfield & Dovidio, 2013;
Levin, Federico, Sidanius, & Rabinowitz, 2002; Saguy,
Tausch, Dovidio, & Pratto, 2009; Ufkes, Calcagno, Glasford,
& Dovidio, 2016). We believe that our paradigm can be
applied to a range of other ethnic groups in conflict. Beyond
Arabs and Jews, numerous recent violent clashes have
occurred between groups that share striking genetic similari-
ties, including Kurds, Armenians, and Turks (Arnaiz-Villena,
Gomez-Casado, & Martinez-Laso, 2002); Indians and
Pakistanis in Kashmir (Reich, Thangaraj, Patterson, Price, &
Singh, 2009); Tamils and Sinhalese in Sri Lanka (Ranaweera
et al., 2014); Russians and Ukrainians (Balanovsky et al.,
2008); and the English and Irish (Oppenheimer, 2007). Yet,
given peoples’ limited understanding of genes (Lanie et al.,
2004) and that historical accounts, cultural myths, and con-
flicting genetic analyses also suggest distinct lineages, these
groups are likely to be unaware of their actual degree of
genetically overlap. Thus, altering awareness of genetic
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Kimel et al. 11
differences and similarities may impact peace and conflict in
these contexts as well. At the same time, we also believe that
our paradigm can be applied to ethnic groups without a
recent history of conflict (e.g., Asians and Blacks). Indeed,
future research could directly compare the impact of genetic
information on intergroup bias within contexts of varying
degree of intergroup hostility and threat. Such an approach
could give more direct information about contextual modera-
tors that may underlie our effects.
Societal Implications
Based on our findings, we suggest that conflict-monitoring
organizations (e.g., International Crisis Group, Genocide
Watch) go on heightened alert when conflict-rhetoric begins
emphasizing genetic differences. In addition, we encourage
further exploration of the potential benefits of interventions
that educate about high degrees of genetic overlap between
groups in conflict. Because it is often assumed that genes are a
meaningful way to think about racial and ethnic group mem-
bership (Yzerbyt, Corneille, & Estrada, 2001), we also encour-
age interventions that create greater awareness of the
considerable amount of genetic overlap that exists between all
of the world’s ethnic and racial groups (see Plaks et al., 2012).
Lastly, our findings have implications for research and
reporting on the genetic underpinning of ethnic and racial
categories. As such research continues to produce new and
controversial findings, awareness of how this information
can impact lay perceptions is critically important. Indeed, in
an effort to vie for media attention, researchers often contrib-
ute to the media’s oversimplified and deterministic explana-
tions of genes (Bubela & Caulfield, 2004). As most people’s
understanding of genetics comes from these media accounts
(Conrad, 1999), researchers should be particularly cautious
when formulating press releases about the degree of intereth-
nic genetic overlap—their findings and interpretations may
have far-reaching consequences.
Acknowledgments
The author(s) would like to thank the reviewers and the editor for
their feedback and suggestions that helped us improving this
article.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect
to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, author-
ship, and/or publication of this article.
Notes
1. For instance, in 1994, leading up to the Bosnian genocide,
Biljana Plavsic, the former President of Republika Srpska,
said, “We are upset by a rising number of mixed marriages
between Serbs and Muslims, for they allow genes to be
exchanged between ethnic groups, and lead subsequently to
the degeneration of Serb nationality” (Oslobođenje, May 1994,
cited in Subotić 2012).
2. “Tutsi Probably Differ Genetically From the Hutu,” accessed
January 18, 2015. http://blogs.discovermagazine.com/gnxp/2011/
08/tutsi-differ-genetically-from-the-hutu/#.VLvs1GTF9TM
3. “Genes of Most Ashkenazi Jews Trace Back to Indigenous
Europe, Not Middle East,” accessed January 18, 2015. http://
www.medicaldaily.com/genes-most-ashkenazi-jews-trace-
back-indigenous-europe-not-middle-east-259321
4. “European Roma Descended From Indian ‘untouchables,’
genetic study shows,” accessed January 18, 2015. http://www.
telegraph.co.uk/news/worldnews/europe/9719058/European-
Roma-descended-from-Indian-untouchables-genetic-study-
shows.html
5. “Consumer Genomics Market Should Pass ‘Tipping Point’ of 3
Million Samples Tested in 2015,” accessed December 8, 2015.
https://www.genomeweb.com/microarrays-multiplexing/con-
sumer-genomics-market-should-pass-tipping-point-3-million-
samples-tested
6. Only 1% expressed suspicion that we might have been examin-
ing the influence of the article on their subsequent attitudes. Our
subsequent studies showed similar rates.
7. The survey also consisted of unpublished exploratory measures
which are not presented here.
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