Ideological differences in the expanse of the moral circle

Abstract

Do clashes between ideologies reflect policy differences or something more fundamental? The present research suggests they reflect core psychological differences such that liberals express compassion toward less structured and more encompassing entities (i.e., universalism), whereas conservatives express compassion toward more well-defined and less encompassing entities (i.e., parochialism). Here we report seven studies illustrating universalist versus parochial differences in compassion. Studies 1a-1c show that liberals, relative to conservatives, express greater moral concern toward friends relative to family, and the world relative to the nation. Studies 2a-2b demonstrate these universalist versus parochial preferences extend toward simple shapes depicted as proxies for loose versus tight social circles. Using stimuli devoid of political relevance demonstrates that the universalist-parochialist distinction does not simply reflect differing policy preferences. Studies 3a-3b indicate these universalist versus parochial tendencies extend to humans versus nonhumans more generally, demonstrating the breadth of these psychological differences.

Full text

ARTICLE
Ideological differences in the expanse of the
moral circle
Adam Waytz1, Ravi Iyer2, Liane Young3, Jonathan Haidt4& Jesse Graham5
Do clashes between ideologies reflect policy differences or something more fundamental?
The present research suggests they reflect core psychological differences such that liberals
express compassion toward less structured and more encompassing entities (i.e., uni-
versalism), whereas conservatives express compassion toward more well-defined and less
encompassing entities (i.e., parochialism). Here we report seven studies illustrating uni-
versalist versus parochial differences in compassion. Studies 1a-1c show that liberals, relative
to conservatives, express greater moral concern toward friends relative to family, and the
world relative to the nation. Studies 2a-2b demonstrate these universalist versus parochial
preferences extend toward simple shapes depicted as proxies for loose versus tight social
circles. Using stimuli devoid of political relevance demonstrates that the universalist-
parochialist distinction does not simply reflect differing policy preferences. Studies 3a-3b
indicate these universalist versus parochial tendencies extend to humans versus nonhumans
more generally, demonstrating the breadth of these psychological differences.
https://doi.org/10.1038/s41467-019-12227-0 OPEN
1Northwestern University, 2211 Campus Dr, Evanston, IL 60208, USA. 2Facebook, 12721W Jefferson Blvd, Los Angeles, CA 90066, USA. 3Boston College,
Gasson Hall, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA. 4New York University, Kaufman Management Center, 44 West Fourth Street, 7-
98, New York, NY 10012, USA. 5University of Utah, Spencer Fox Eccles Business Building, 1655 East Campus Center Drive, Salt Lake City, UT 84112, USA.
Correspondence and requests for materials should be addressed to A.W. (email: a-waytz@kellogg.northwestern.edu)
NATURE COMMUNICATIONS | (2019) 10:4389 | https://doi.org/10.1038/s41467-019-12227-0 | www.nature.com/naturecommunications 1
1234567890():,;
Content courtesy of Springer Nature, terms of use apply. Rights reserved

In 2006, then Democratic Senator Barack Obama bemoaned
the country’s“empathy deficit,”telling college graduates, “I
hope you choose to broaden, and not contract, your ambit of
concern.”In 2012, Republican presidential challenger Mitt
Romney said, “President Obama promised to begin to slow the
rise of the oceans and heal the planet. My promise is to help you
and your family.”
The distinction between Obama and Romney captures the
distinct worldviews of American political liberals and con-
servatives, respectively. Romney prioritized the family unit,
whereas Obama highlighted the planet broadly. This difference in
parochialism versus universalism became exacerbated during the
2016 presidential election, with one article noting, “Trump vs.
Hillary Is Nationalism vs. Globalism, 20161,”contrasting the
more parochial Republican candidate with the more universalist
Democratic candidate. Others have characterized the Trump
administration’s policy decisions as battles between nationalists
(typified by parochialism) and globalists (typified by uni-
versalism)2.
These differential tendencies toward parochialism and uni-
versalism on the political right and left, respectively, extend
beyond the United States as well. For example, leading French
right-wing politician, Marie Le Pen declared in 2016, “The gap is
not between the Left and the Right, but between globalists and
patriots. The globalists are acting for the dilution of France and its
people in a huge worldwide magma. The patriots hope that the
nation constitutes the most protective space for the French3.”
Across Western Europe, ideological battles between the left and
right have centered on this tension between universalism and
parochialism.
Universalism refers to moral regard directed toward more
socially distant and structurally looser targets, relative to socially
closer and structurally tighter targets. Parochialism refers to
moral regard directed toward socially closer and structurally
tighter targets, relative to socially more distant and structurally
looser targets. Universalist moral circles and parochial moral
circles in this context are concentric, with one encompassing the
other. These circles refer to groups of targets toward which one
expends moral regard, and reflect the concept of moral circles
popularized by Singer4(see also Burke5). They are akin to the idea
of moral communities that comprise one’s in groups (discussed
by Deutsch et al.6,7), in which entities can be included or excluded
as worthy of moral regard, as well as to concentric circles of
identity defined by self-categorization theory (whereby one’s self-
concept can include increasingly distant social groups depending
on one’s level of abstraction)8. While “parochial”sometimes has a
negative connotation, we do not imply any such evaluation here
and simply use it to describe maintaining a tight (versus loose)
moral circle.
Previous research supports this universalist–parochial distinc-
tion between liberals and conservatives9. For instance, con-
servatives, relative to liberals, express greater need for closure,
order, and structure10–12. Personality research shows social lib-
erals consistently score higher on openness, whereas social con-
servatives score higher on conscientiousness13. Taken together,
existing work suggests that political conservatism reflects a
greater tendency to seek structure, to avoid ambiguity, changes to
the status quo, and novelty. By this account, political liberalism
represents greater comfort with lack of structure, new experi-
ences, and novel information.
Given ideological differences in open versus closed styles of
information processing, moral concern might follow a similar
pattern. In prioritizing closure, order, and stability, conservatives
should express concern toward smaller, more well-defined, and
less permeable social circles (relative to broader ones). In prior-
itizing openness, tolerance for ambiguity, and desire for change,
liberals should express concern toward larger, less well-defined,
and more permeable social circles (relative to smaller ones).
Beyond low-level cognitive and motivational differences, one
additional line of work supports the ideological distinction between
parochial–universalist differences in compassion. This line of
research stems from Moral Foundations Theory (MFT)14–16,
which characterizes liberals and conservatives as diverging along
two classes of intuitive moral values. Liberals care about harm and
fairness (individualizing values), whereas conservatives care more
about loyalty, authority, and sanctity (binding values). This
research again suggests a differing focus such that liberals tend to
express compassion toward individuals broadly construed, whereas
conservatives emphasize compassion toward their immediate
social groups. Supporting this idea, separate work indeed found
that endorsement of individualizing values is positively correlated
with moral expansiveness (moral consideration for entities,
including plants and animals, beyond one’s immediate in group)
whereas endorsement of binding values is negatively correlated
with moral expansiveness17.
The present research provides empirical evidence for these
differing ideological patterns of compassion and extends these
patterns to stimuli across a range of measures. This work also
shows these broader ideological differences are rooted in per-
ceptual differences. These differences appear to stem also from a
broader historical trend that has accelerated in recent decades as
most countries have become wealthier and safer. Christian Wel-
zel, a lead researcher for the World Values Survey, has described
how reduced “existential threats”change values:
Fading existential pressures open people’s minds, making
them prioritize freedom over security, autonomy over
authority, diversity over uniformity, and creativity over
discipline…the existentially relieved state of mind is the
source of tolerance and solidarity beyond one’s in group18.
Our research is consistent with Welzel’s characterization of the
general shift from “survival values”that increase dependence on
close others, to “emancipative values”that downplay local ties—
and loyalties—and lead people to look farther afield for social
relationships.
These studies aim to connect Singer’s4idea of the moral circle
to empirical political psychology. Beyond demonstrating a
universalist–parochial distinction between liberals and con-
servatives, this research examines whether this distinction reflects
mere political preferences, or something deeper. Universalism
may reflect favorability toward policies that promote open bor-
ders (and encourage immigration) and that promote diplomacy
toward ostensibly hostile nations. Such policies represent
extending moral regard beyond one’s immediate group (e.g., the
nation) and to the world more broadly. Similarly, parochialism
may reflect favorability toward stricter immigration policies and
defense spending to protect one’s nation—these policies represent
prioritizing the well-being of one’s own nation at the potential
expense of others. On the other hand, if the universalist–parochial
distinction reflects a worldview beyond policy interests, then it
should reflect evaluations of stimuli completely devoid of social or
political relevance, for example abstract, animate shapes. Thus,
we tested whether liberals and conservatives would display uni-
versalist and parochialist tendencies, respectively, in terms basic
perceptual preferences. Finally, we examined whether this
universalist–parochialist difference would map on to moral
concern for humans exclusively versus a broader conception of
the moral universe that includes nonhumans as well. Importantly,
this work uses both measures developed for this work that
explicitly capture the expanse of one’s moral circle as well as
established measures that assess moral consideration for specific
targets, to provide convergent evidence across studies.
ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-12227-0
2NATURE COMMUNICATIONS | (2019) 10:4389 | https://doi.org/10.1038/s41467-019-12227-0 | www.nature.com/naturecommunications
Content courtesy of Springer Nature, terms of use apply. Rights reserved

Studies 1a–1c examine universalist versus parochial differences
in the domains of friends versus family (friends typically con-
stitute a larger, broader and more diffuse group than family) and
the world versus the nation (the world encompasses one’s
nation). Studies 2a–2b show this universalist–parochial distinc-
tion maps on to abstract entities (animated shapes) distinguished
only by low-level perceptual properties. Studies 3a–3b demon-
strate that this universalist–parochial distinction maps on to
moral concern for humans exclusively compared with a social
world that includes nonhumans. Across studies, we predicted that
liberalism versus conservatism would be associated with uni-
versalism relative to parochialism, even in the context of pre-
ference for shapes devoid of social relevance and humans versus
nonhumans.
Results
For all results in this paper, p-values that follow the label rwere
generated from Pearson’s correlations and p-values that follow
standardized betas were generated from t-tests on regressions. All
other statistical tests are specified.
Study 1a tests the hypothesis that liberalism and conservatism
would correlate with love for friends and love for family,
respectively. The results showed conservatism was positively
related to love of family, r(3,362) =0.065, p< 0.001, and nega-
tively related to love of friends, r(3,360) =−0.065, p< 0.001 (for
means, see Fig. 1) (see Supplementary Note 2 for exploration of
quadratic effects). Admittedly, these correlations are exceedingly
small and should be interpreted with caution. Critically, however,
Steiger z-tests conducted on participants who had scores for each
of these scales demonstrated that these correlations differed from
each other (zs > 2.87, ps < 0.004). In addition, conservatism was
unrelated to romantic love (r=−0.01, p=0.68) (a construct that
combines friendship and family relations) and was negatively
correlated with love for all others, r(3,362) =−0.20, p< 0.001—
this result suggests liberalism is associated with a more uni-
versalist sense of compassion.
Separate multiple regressions in which romantic love, love of
friends, love of family, and love of all others were the outcome
variables and political ideology, age, gender, and education were
predictor variables revealed that the effect of political ideology
remained the same—significant for love of friends, love of family,
love of all others, and nonsignificant for romantic love (see Table 1
for standardized betas). These analyses suggest that political
ideology meaningfully affects love of friends, family, and others
universally, independent of other related demographic variables.
Study 1b tests the hypothesis that just as liberalism and con-
servatism will correspond to valuing the world and valuing the
nation, respectively. Conservative ideology was negatively corre-
lated with universalism, r(13,154) =−0.41, p< 0.001, again
demonstrating that conservatism is negatively related to a uni-
versal love of others, whereas liberalism is positively related to
this sense of universal compassion. In addition, conservative
ideology was positively correlated with nationalism, r(13,030) =
0.46, p< 0.001 (see Fig. 2for means). A Steiger ztest on parti-
cipants who had scores on both of these measures demonstrated
that these correlations differed significantly from one another
(z=77.04, p< 0.001).
Separate multiple regressions in which universalism and
nationalism were the outcome variables, respectively and political
ideology, age, gender, and education were predictor variables,
revealed that the effect of political ideology persisted (see
Table 1). Liberalism continued to predict universalism sig-
nificantly whereas conservatism continued to predict nationalism
significantly. These findings suggest that political ideology
meaningfully affects universalism and nationalism, independent
of other related demographic variables.
Like Study 1b, Study 1c tests the hypothesis that conservatism
corresponds to a more parochial or national sense of compassion
whereas liberalism corresponds to a universal sense of compas-
sion. Conservatism correlated with identification with country, r
(14,176) =0.28, p< 0.001 a liberalism correlated with identifica-
tion with the world, r(14,176) =−0.34, p< 0.001. In addition,
conservatism showed a small but significant correlation with
identification with community, r(14,176) =0.074, p< 0.001.
Steiger ztests demonstrated that the correlations differed sig-
nificantly for community and country (z=26.74, p< 0.001), for
country and all humans (z=67.09, p< 0.001), and for commu-
nity and all humans (z=43.95, p< 0.001) (for means, see Fig. 3).
Separate multiple regressions in which identification with
community, identification with country, and identification with
all humanity were the outcome variables and political ideology,
6
Love of family
Love of friends
Love of all others
4
Rating
2
Very liberal
Liberal
Moderate
Slightly liberal
Slightly conservative
Conservative
Very conservative
Fig. 1 Love by political ideology, Study 1a. Error bars represent standard errors, solid lines indicate means. Source data are provided as a Source Data file
NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-12227-0 ARTICLE
NATURE COMMUNICATIONS | (2019) 10:4389 | https://doi.org/10.1038/s41467-019-12227-0 | www.nature.com/naturecommunications 3
Content courtesy of Springer Nature, terms of use apply. Rights reserved

age, gender, and education were predictor variables revealed that
the effect of political ideology remained the same (see Table 1).
These analyses suggest that political ideology meaningfully affects
identification with community, country, and all humans, inde-
pendent of other related demographic variables.
Studies 1a–1c demonstrate that conservatives are more parochial
than liberals—their moral circles are more constrained. This poli-
tical difference manifests at the level of family versus friends and the
nation versus the world. These differences are perhaps unsurprising
given well-known policy disagreements on issues affecting these
specific circles of family, friends/community, nation, and
world16,19,20. If ideological differences in compassion simply reflect
policy issue differences, then they should affect attitudes toward
targets relevant to these social issues. However, if these ideological
differences permeate more deeply into liberals and conservatives
general worldviews they should manifest in evaluations of targets
completely devoid of social and political relevance. We test this
possibility in Studies 2a and 2b.
Study 2a tested whether conservatives (relative to liberals)
would prefer tight (relative to loose) geometric structures. We
further predicted that these differing preferences would corre-
spond to compassion toward social circles (that involved speci-
fically human targets) examined in Studies 1a–1c. Conservatism
was associated significantly with preference for tightness relative
Table 1 Standardized betas for regressions using political ideology, education, age, and gender
Study Outcome measure Political ideology Education Age Gender
1a Romantic love 0.01 0.05* −0.02 −0.10**
1a Love of family 0.10** 0.05** −0.07** −0.14**
1a Love of friends −0.05** −0.01 −0.015 −0.17**
1a Love of all others −0.17** 0.01 0.175** −0.19**
1b Nationalism 0.45** −0.06** 0.19** −0.035**
1b Universalism −0.42** −0.06** 0.18** −0.13**
1c Identification with community 0.08** 0.06** 0.085** −0.13**
1c Identification with country 0.285** 0.01 0.15** −0.10**
1c Identification with all humanity −0.33** −0.03** 0.04** −0.155**
2a Preference for looseness versus tightness −0.20** 0.01 −0.02 0.003
2a Preference for color diversity −0.03+−0.04* 0.23** −0.05**
2b Preference for looseness versus tightness −0.12** 0.02 −0.06* 0.03
2b Preference for circle versus triangle −0.07** −0.04 −0.01 −0.05+
3a Personal moral allocation to humans 0.34** −0.01 −0.09 0.12
3a Ideal moral allocation to humans 0.28** −0.01 −0.04 0.18*
3a Weighted personal moral circle −0.35** −0.03 0.07 −0.11
3a Weighted ideal moral circle −0.26** −0.02 0.01 −0.15+
3b Proportion moral allocation to humans 0.13* 0.15* 0.08 0.13*
3b Total moral allocation 0.055 0.03 −0.01 −0.09
3b Moral allocation to humans 0.056 0.03 −0.01 −0.09
3b Moral allocation to nonhumans 0.055 0.03 −0.01 −0.09
Notes: +p< 0.09; *p< 0.05; **p< 0.01. Effect of gender for moral allocation to humans (Study 3b) becomes marginally significant (p=0.062) when including the one participant whose total allocation
falls outside of 3SD of the mean
5.0
Nationalism
Universalism
2.5
Rating
0.0
Very liberal
Slightly liberal
Slightly conservative
Very conservative
Conservative
Liberal
Moderate
Fig. 2 Endorsement of values by political ideology, Study 1b. Error bars represent standard errors, solid lines indicate means. Source data are provided as a
Source Data file
ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-12227-0
4NATURE COMMUNICATIONS | (2019) 10:4389 | https://doi.org/10.1038/s41467-019-12227-0 | www.nature.com/naturecommunications
Content courtesy of Springer Nature, terms of use apply. Rights reserved

to looseness in geometric structures, r(4426) =−0.20, p< 0.001.
These results suggest, as predicted, conservatism relative to lib-
eralism corresponds to a preference for tighter structures even
when devoid of social relevance.
We also predicted, a priori, that liberals would show a pre-
ference for color diversity (i.e., the different colors represented by
the geometric structures) across stimuli, but found no significant
correlation, r=−0.01, p=0.35. This finding suggests that
ideology specifically relates to preference for the movement pat-
terns of the structures, and not more broadly related to their
homogeneity or heterogeneity.
Separate multiple regressions in which preference for
looseness-tightness and preference for diversity of color were the
outcome variables, respectively, and political ideology, age, gen-
der, and education were predictor variables revealed that political
ideology continued to predict looseness-tightness preference sig-
nificantly. In addition, a multiple regression revealed that pre-
ference for diversity was in the predicted direction (associated
positively with liberal ideology), but the effect was tiny and only
of marginal significance (p=0.078) (see Table 1). These analyses
suggest that political ideology meaningfully affects this basic
preference for geometric looseness-tightness, independent of
other related demographic variables.
Ideology could be linked to geometric preferences in ways
completely unrelated to the link between ideology and social
preferences. We therefore examined whether this basic preference
for geometric structure maps on to social judgments, testing
whether this preference helps account for the relationship
between political ideology and moral regard for tight versus loose
social structures examined in previous studies.
We tested this by capitalizing on a unique subset of partici-
pants who—in addition to completing this study—had also
completed one of Studies 1a, 1b, and 1c. These participants
enabled us to examine the association between scores on the
present geometric shapes task and a social looseness-tightness
score reflecting participants’preference for small social circles
(i.e., family and the nation) relative to larger social circles (i.e.,
friends and the world, respectively).
For each participant, we computed a social looseness–tightness
score by first standardizing all measures in Studies 1a–1c, and
then averaging scores for explicitly “tight”circles and subtracting
this average from the average of scores for explicitly “loose”cir-
cles. In other words, we computed the average of standardized
scores for the love of family scale (Study 1a), the national security
subscale (Study 1b), and the identification with country subscale
(Study 1c) (“tight measures”), and computed the average of
standardized scores for the love of friends and love for all other
subscales (Study 1a), the universalism subscale (Study 1b), and
the identification of all humanity subscale (Study 1c) (“loose
measures”). We then subtracted the average of loose measures
from the average of tight measures as follows:
(average (love for friends
Study1a
, love for all others
Study1a
,
value of universalism
Study1b
,identification with all
humanity
Study1c
)) −(average (love of family
Study1a
,valueof
national security
Study1b
,identification with country
Study1c
)).
To maximize statistical power, we included people who did not
have scores for all measures in the equation, although scores were
not computed for people who only had scores for the tight or
loose side of the equation, leaving 921 participants. In other
words, this score reflected participants’moral regard for friends
and global humanity relative to family and one’s nation.
We then used bootstrapping mediation analysis using the SPSS
PROCESS macro21 (bias-corrected, 20,000 resamples) to examine
whether preference for geometric looseness-tightness mediates
the relationship between political ideology and social looseness-
tightness. This analysis confirmed partial mediation, in that
political ideology indirectly affected people’s preference for
social looseness–tightness through a preference for geometric
looseness–tightness (95% confidence interval =−0.02 to
−0.0002).
Thus, at very least, the relationship between ideology and
preference for geometric looseness–tightness is related to pre-
ference for social looseness–tightness, and this more “primitive”
preference for looseness–tightness might drive people of different
political ideologies toward social circles of different expansive-
ness. Most important, this study demonstrates that the looseness-
tightness preference is not limited to circles with which people
have preexisting associations, and this perceptual preference is
linked to a preference for more well-defined tight versus loose
5
4
3
Identification with community
Identification with country
Identification with all humanity
Rating
2
1
Very liberal
Liberal
Slightly liberal
Slightly conservative
Conservative
Very conservative
Moderate
Fig. 3 Identification by political ideology, Study 1c. Error bars represent standard errors, solid lines indicate means. Source data are provided as a Source
Data file
NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-12227-0 ARTICLE
NATURE COMMUNICATIONS | (2019) 10:4389 | https://doi.org/10.1038/s41467-019-12227-0 | www.nature.com/naturecommunications 5
Content courtesy of Springer Nature, terms of use apply. Rights reserved

social circles. Study 2b provides a conceptual replication to
examine these effects further.
Study 2b is a conceptual replication of Study 2a that again
manipulated tightness versus looseness. Conservatism was asso-
ciated significantly with preference for tightness relative to loos-
eness, r(2072) =−0.15, p< 0.001. These results suggest that
again, as predicted, conservatism relative to liberalism corre-
sponds to an overall preference for tighter structures even when
these structures are devoid of social relevance.
As we presented geometric structures of different shapes, we
had also predicted that conservatives would prefer the shape of a
triangle more often than liberals, and liberals would prefer the
circle more often than conservatives (because it is the most
“egalitarian”shape, with no dot seeming more important than
any other). This prediction was confirmed, marginally: con-
servatives relative to liberals slightly preferred the triangle relative
to the circle, r(2072) =−0.04, p=0.054.
Separate multiple regressions in which preference for
looseness-tightness and preference for circle were the outcome
variables, respectively, and political ideology, age, gender, and
education were predictor variables revealed that political ideology
predicted looseness-tightness preference and preference for shape
significantly (see Table 1). These analyses again suggest that
political ideology meaningfully affects this basic preference for
geometric looseness-tightness, independent of other related
demographic variables.
Again, to examine the relationship between ideology, geometric
looseness–tightness preference, and social looseness–tightness
preference, we computed the same social looseness–tightness
score as in Study 2a and conducted the same mediation analysis
as in Study 2a. This analysis, with 679 participants, also con-
firmed partial mediation—political ideology indirectly affected
people’s preference for social looseness–tightness through a pre-
ference for geometric looseness–tightness (95% confidence
interval =−0.04 to −0.095). These findings again suggest that the
relationship between ideology and geometric looseness–tightness
maps on to preferences for social looseness–tightness.
Building on Studies 1–2, showing that liberals and con-
servatives demonstrate universalism versus parochialism,
respectively, Study 3 tests whether this pattern extends to eva-
luations of nonhumans versus humans, testing the hypothesis
that liberals relative to conservatives will show more moral con-
cern toward nonhuman (relative to human) targets. Although
existing work shows ideologies associated with conservatism like
social dominance orientation and right-wing authoritarianism
predict beliefs in human superiority over nonhuman animals and
positive attitudes toward animal exploitation22,23, the studies here
explicitly test the relationship between political ideology and
moral concern toward humans versus nonhumans.
We analyzed separately participants’ideal and personal allo-
cations of moral regard (measured through “points”described to
participants as “moral units”) to different social circles, some of
which were clearly human (e.g., family) and some of which were
nonhuman (e.g., plants and animals). Political conservatism
correlated with actual moral allocation to humans only, r(129) =
0.32, p< 0.001, and ideal moral allocation to humans only, r
(129) =0.26, p=0.003. Allocation to humans only is directly
inversely correlated with allocation to nonhumans, so correlations
of the same magnitude emerged in the opposite direction for
allocation to nonhumans.
As Fig. 4shows, the more liberal people were, the more they
allocated equally to humans and nonhumans. The further to the
right on the ideological spectrum people were, the more likely
they were to morally prioritize humans over nonhumans.
We also computed a weighted circle score for each participant
by multiplying the numerical rank of each category by the
allocation to that category and summing these values. That is, we
multiplied “immediate family”by 1, “extended family”by 2…“all
things in existence”by 16, and summed the values—larger scores
indicated larger moral circles. The significant correlation between
ideology and this weighted circle score (r(129) =−0.33, p<
0.001; r(129) =−0.24, p=0.005 for ideal allocation), again
demonstrates that as conservatism increases, the extent of the
moral circle decreases.
Separate multiple regressions using personal moral allocation
to humans, ideal moral allocation to humans, weighted personal
circle score, and weighted ideal circle score as outcome variables,
with political ideology, age, gender, and education as predictor
variables, revealed the same significant effects for political ideol-
ogy in all cases (see Table 1). These analyses suggest that political
ideology meaningfully affects moral allocation independent of
related demographic variables.
Finally, we assessed the heatmaps generated by participants’
clicks on the rung they felt best represented the extent of their
moral circle. These qualitative results also demonstrated that
liberals (individuals who selected 1, 2, or 3 on the ideology
measure) selected more outer rungs, whereas conservatives
(individuals who selected 5, 6, or 7 on the ideology measure)
selected more inner rungs (see Fig. 5). Overall, these results
suggest conservatives’moral circles are more likely to encompass
human beings, but not other animals or lifeforms whereas lib-
erals’moral circles are more likely to include nonhumans (even
aliens and rocks) as well. Study 3a revealed these patterns also
when asking about participants’ideal moral circles. This suggests
that both liberals and conservatives, although differing in their
moral allocations, feel that their pattern of allocation is the ideal
way to adjudicate moral concern in the world.
One caveat to Study 3a is that we constrained the number of
units that participants could assign to each group, forcing parti-
cipants to distribute moral concern in a zero-sum fashion (i.e., the
more concern they allocate to one circle, the less they can allocate
to another circle). Although research suggests that people indeed
do distribute empathy and moral concern in a zero-sum fash-
ion24–26, this feature of Study 3a imposes an artificial constraint.
Therefore, to examine whether a similar pattern would emerge
without this constraint, we conducted Study 3b to test whether
the effect would replicate using unlimited units.
Study 3b is a conceptual replication of Study 3a, allowing
participants unlimited moral units to distribute to various circles.
Conservatism was positively correlated with the human allocation
proportion score only, r(261) =0.14, p=0.025, and hence
negatively with the nonhuman allocation proportion score (for
means, see Fig. 6). A multiple regression using the human allo-
cation proportion score as an outcome variable with political
ideology, age, gender, and education as predictor variables
revealed the same significant effect for political ideology (see
Table 1). Thus, even when participants’allocations were not
constrained, the same pattern replicated such that liberals dis-
tribute empathy toward broader circles and conservatives dis-
tribute empathy toward smaller circles.
Importantly, in addition to examining proportion, we also
examined total allocation, and allocation to humans and to
nonhumans. Liberals and conservatives did not differ such that
political ideology was not significantly correlated with total allo-
cation to all targets, r(261) =0.04, p=0.51, total allocation to
humans, r(261) =0.04, p=0.50, or total allocation to nonhu-
mans, r(261) =0.04, p=0.51 (this pattern of the results was the
same when excluding the one participant whose allocations fell
outside of 3SD of the mean; see below). Separate multiple
regressions using these total allocation scores as outcome vari-
ables with political ideology, age, gender, and education as pre-
dictor variables revealed the same nonsignificant effects for
ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-12227-0
6NATURE COMMUNICATIONS | (2019) 10:4389 | https://doi.org/10.1038/s41467-019-12227-0 | www.nature.com/naturecommunications
Content courtesy of Springer Nature, terms of use apply. Rights reserved

political ideology (see Table 1). Again, these findings demonstrate
that liberals and conservatives differ not in the total amount of
moral regard per se but rather they differ in their patterns of how
they distribute their moral regard.
Discussion
Seven studies demonstrated that liberals relative to conservatives
exhibit universalism relative to parochialism. This difference
manifested in conservatives exhibiting greater concern and pre-
ference for family relative to friends, the nation relative to the
world, tight relative to loose perceptual structures devoid of social
content, and humans relative to nonhumans.
Others have identified this universalist–parochial distinction,
with Haidt27, for example, noting “Liberals…are more uni-
versalistic…Conservatives, in contrast, are more parochial—
concerned about their groups, rather than all of humanity.”The
present findings comprehensively support this distinction
empirically, explicitly demonstrating the relationship between
ideology and universalism versus parochialism, assessing judg-
ments of multiple social circles, and providing converging evi-
dence across diverse measures.
15
Human
Nonhuman
10
Rating
5
0
Very liberal
Liberal
Slightly liberal
Slightly conservative
Conservative
Very conservative
Moderate
Fig. 4 Personal moral allocation to humans and nonhumans by political ideology, Study 3a. Error bars represent standard errors, solid lines indicate means.
Source data are provided as a Source Data file
Liberals
Conservatives
0120 20
Fig. 5 Heatmaps indicating highest moral allocation by ideology, Study 3a. Source data are provided as a Source Data file. Note. The highest value on the
heatmap scale is 20 units for liberals, and 12 units for conservatives. Moral circle rings, from inner to outer, are described as follows: (1) all of your
immediate family, (2) all of your extended family, (3) all of your closest friends, (4) all of your friends (including distant ones), (5) all of your
acquaintances, (6) all people you have ever met, (7) all people in your country, (8) all people on your continent, (9) all people on all continents, (10) all
mammals, (11) all amphibians, reptiles, mammals, fish, and birds, (12) all animals on earth including paramecia and amoebae, (13) all animals in the
universe, including alien lifeforms, (14) all living things in the universe including plants and trees, (15) all natural things in the universe including inert
entities such as rocks, (16) all things in existence
NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-12227-0 ARTICLE
NATURE COMMUNICATIONS | (2019) 10:4389 | https://doi.org/10.1038/s41467-019-12227-0 | www.nature.com/naturecommunications 7
Content courtesy of Springer Nature, terms of use apply. Rights reserved

The present research also leaves several open questions for
future examination. Given that we elicited responses from par-
ticipants rather than examining their spontaneous tendencies
toward parochialism or universalism, additional research can
assess whether these patterns of moral concern appear even when
unprompted. Research examining language use on Twitter sup-
ports the parochialism-universalism distinction established here,
demonstrating Republicans discuss topics more related to the
nation, whereas Democrats discuss topics more pertinent to
outside of the home nation28. An additional limitation of the
present research is that we imposed the distinction of universalist
versus parochial on particular circles, and participants might
construe these categorizations differently. For example, liberals
might construe their friends as more of an inner circle than their
family, even though in our operationalization, we treat friends as
a more universalist circle and family as a more parochial circle17.
We imposed distinctions based on objective standards of kinship
(family vs. friends) and nationality (nation vs. world), but dif-
ferent patterns of the results might emerge using different
parochial–universalist comparisons between different circles (e.g.,
nation vs. friends).
A separate issue concerns causality. Although our research fol-
lows the predominant norms in political ideology research in
treating ideology at the independent variable, in some cases
ideology could also serve as the dependent variable. That is, moral
regard toward particular social circles could alter one’spolitical
ideology over time as well. Rather than a dichotomous chicken-or-
egg question (does ideology cause differences in concern, or do
differences in concern cause ideology?), the relations between
ideology and ambit of concern are likely a complex interplay across
development involving interactions between genetic and environ-
mental factors29.Bothone’s ambit of concern and political ideology
are likely preceded by basic temperamental differences demon-
strated by research in developmental psychology30 and political
science31. Future work can delineate these causal pathways.
An additional question regarding causality concerns the rela-
tionship between low-level perceptual differences in looseness-
tightness that emerge in Studies 2a–2b and differences in broader
social tendencies toward parochialism-universalism. Although
again we cannot fully establish causality, we believe these per-
ceptual preferences for tightness versus looseness reflect basic
differences in information processing (desire for closure and
structure versus desire for openness), which in turn drive pre-
ferences for tighter versus looser social circles. In this way, our
work is similar to work showing that left–right ideological dif-
ferences manifest in basic information processing differences in
orientation toward appetitive versus aversive stimuli32 and
exploration versus non-exploration toward novel stimuli33 (even
when these stimuli are devoid of social meaning). Our work also
demonstrates specific perceptual differences (in Studies 2a–2b)
and connects these more fundamental information processing
differences to social preferences, moral foundations, and moral
expansiveness broadly.
An additional direction for future research is to examine the
relationship between ambit of concern and ideology beyond a
simple liberal–conservative distinction. Although we employ a
general measure of ideology and demonstrate that economic and
social ideology reveal the same patterns of the results, in some
circumstances social ideology might capture ambit of concern
better than economic ideology. Additional research can examine
the specifically social component of ideology specifically. We also
do not examine the relationship between ideology and ambit of
concern for libertarians, a group that exhibits low general
empathy, low universalism, but also low endorsement of the
binding moral foundations that typify conservative ideology34.
Additional research examining libertarians can better capture
moral concern beyond the simple liberal–conservative dimension.
Finally, future research can address three issues pertaining to
generalizability. First, future work can address manifestations of
ideology at different time periods, as we cannot make overly
broad claims about ideology based on data from this one (par-
ticularly polarized) point in history.35 Nonetheless, we do believe
that the left–right distinction is quite robust throughout history
even as it takes different forms from generation to generation. As
Hibbing31 notes, John Stuart Mill called it “commonplace”for
political systems to have “‘a party of order or stability and a party
of progress or reform’… The antagonism between two primal
mindsets certainly pervades human history: Sparta and Athens;
1.00
0.75
0.50 Humans
Nonhumans
Proportion
0.25
0.00
Very liberal
Liberal
Slightly liberal
Moderate
Slightly conservative
Conservative
Very conservative
Fig. 6 Proportion of moral allocation by ideology, Study 3b. Error bars represent standard errors, solid lines indicate means. Source data are provided as a
Source Data file
ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-12227-0
8NATURE COMMUNICATIONS | (2019) 10:4389 | https://doi.org/10.1038/s41467-019-12227-0 | www.nature.com/naturecommunications
Content courtesy of Springer Nature, terms of use apply. Rights reserved

optimates and populares; Roundheads and Cavaliers; Inquisition
and Enlightenment; Protagonus and Plato; Pope Urban VIII and
Galileo; Barry Goldwater and George McGovern; Sarah Palin
and Hillary Rodham Clinton. The labels “liberal”or “leftist”and
“conservative”or “rightist”may be relatively recent (etymologi-
cally they are typically assumed to date to the French Revolution,
but they appear to be much older.”
The second issue pertaining to generalizability is sample
representativeness. The present research used participants
samples from platforms that were not necessarily representa-
tive and contained more political liberals than conservatives.
To bolster our findings here that liberals relative to con-
servatives exhibit universalism relative to parochialism, we
examined nationally representative data from the United States
in the World Values Survey in a supplementary study (see
Supplementary Methods). This study again demonstrated
universalism–parochialism differences that manifested in
conservatives (relative to liberals) exhibiting greater concern
and preference for family relative to friends, the nation relative
to the world, and humans relative to nonhumans. In addition,
this data contain participants from multiple time periods
from 1994 to 2014, suggesting—and speaking to the point
raised in the previous paragraph—that the general patterns we
find here are not specific to this singular moment in time.
The third issue concerns whether the findings here extend
beyond the United States. The United States was the focus of
the present work, but we acknowledge that other countries
could show differing patterns. One possible reason is simply
semantic—that is, “liberal”means different things in different
countries, with the “Liberal Party”of Australia, for example,
representing a center–right ideological position. In these stu-
dies, we address this issue by indicating for non-US partici-
pants in Studies 1a–2b’s instructions, that “liberal”refers to
“progressives”and the political left whereas “conservatives”
refers to “traditionalists”and the political right. Non-US par-
ticipants in these studies, therefore, show the same pattern of
results as US participants (see Supplementary Note 5). On the
other hand, given differing historical trajectories and cultural
norms around conceptualizations of friends, family, the nation,
the world, humans, and nature these patterns may vary in
certain contexts.
As one initial test of this, we examined countries from
similar backgrounds as the United States including Canada,
Australia, and Western Europe and also examined Eastern
European countries, many of which have a history under a
Communist regime. Whereas the countries similar to the
United States showed the same pattern of results in terms of
universalism versus parochialism, more variance emerged in
the Eastern European countries (see Supplementary Table 1).
Rather than attempt to explain all regional differences, we urge
additional future research on cross-cultural comparisons. We
continue to predict that, because conservative and liberal
ideologies represent consistent sets of psychological differ-
ences36 in terms of motivational and cognitive processing
styles, any ideology corresponding to a more closed and
ordered mode of information processing will manifest in par-
ochialism whereas any ideology corresponding to a more open
and unstructured mode of information processing will man-
ifest in universalism.
While people across the ideological spectrum all likely
experience both centripetal and centrifugal forces in their ambits
of concern37, liberals are more likely to distribute concern to
outer circles and conservatives are more likely to distribute
concern to inner circles. This suggests that it is the differential
distribution of concern that contributes to and exacerbates moral
debates across the political divide.
Methods
All studies were institutional review board-approved by University of Southern
California and Northwestern University and participants provided informed con-
sent for each one.
Study 1a, participants. Three thousand three hundred sixty-four participants
(1791 male, M
age
=34.94, SD =13.64) completed the study on the YourMorals.org
website. At this website, participants first registered by completing basic demo-
graphic information including gender (0 =female, 1 =male), age (coded as blank
if values > 95 to reduce fraudulent responses), and education (1 =some high
school, 2 =currently in high school, 3 =completed high school, 4 =some college
or university, 5 =currently in college, 6 =completed college or university, 7 =
some graduate/professional school, 8 =currently in graduate or professional
school, 9 =completed graduate or professional school; no answer =blank). In this
study and all others conducted on YourMorals.org, removing participants who also
completed one of the studies here or a study on YourMorals.org assessing a similar
construct did not change the primary pattern of results.
Participants also indicated their political ideology (very liberal =1, liberal =2,
slightly liberal =3, moderate =4, slightly conservative =5, conservative =6, very
conservative =7, and libertarian, do not know/not political, or other, the last three
of which were excluded from analyses in this and all other studies). This ideology
rating scale for YourMorals.org studies was also described to participants in a way
that it could translate to countries with different conceptualizations of liberal/
conservative:
“(The terms used in your country may differ. “Liberal”is intended to
include the Left, progressives, and in some countries socialists. “Con-
servative”is intended to include the Right, traditionalists, and in some
countries Christian Democrats.)”
There were 2619 liberals, 347 moderates, and 398 conservatives. In this study
and all others conducted on YourMorals.org, some participants also separately
indicated their ideology “on social issues”and “on economic issues”using the same
options for the general political ideology question. Where these data are available
from our participants, we also conduct primary analyses using measures of social
and economic ideology and report them in Supplementary Note 3. Also see
Supplementary Note 1 for more information on the samples obtained on
YourMorals.org.
Procedure. Participants completed the love of humanity scale38 that includes four
subscales (1 =completely disagree, 7 =completely agree): romantic love (e.g., “My
romantic partner and I are drawn to each other”), love for friends (e.g., “My friends
and I look out for each other”), love for family (e.g., “My siblings and I love each
other “warts and all”—we don’t censor ourselves around each other”), and love for
all others (there are times in my life when I’ve felt strong feelings of love for all
people, not just the specific people I’m close to”). Although all participants received
all items, not all participants produced scores for every subscale (failing to answer
any items pertaining to a specific subscale). Participants were included if they
produced scores for at least one of these subscales, but not the others, resulting
sometimes in slightly different degrees of freedom across subscales. This same
specification applies to Studies 1b and 1c, which also contain subscales.
Study 1b, participants. Thirteen thousand one hundred fifty-six participants
(7113 male, M
age
=36.72 SD =14.47) completed the study on the YourMorals.org
website. During registration participants completed the same ideology, age, gender,
and education measures described in Study 1a and in this sample consisted of 9625
liberals, 1684 moderates, and 1847 conservatives.
Procedure. Participants completed the Schwartz Values Inventory39, which
assesses various values that act as guiding principles for one’s life. Of importance
were two measures in particular, one assessing values oriented toward the world as
a whole—a set of items examining universalism, the concept of peace and equality
for all (e.g., “A WORLD AT PEACE—free of war and conflict”)—and one item
assessing nationalism (“NATIONAL SECURITY (protection of my nation from
enemies”). Participants answered how important 58 value items were for their lives,
and used a scale ranging from −1 (opposed to the value) to 0 (not at all important)
to 7 (of supreme importance).
Study 1c, participants. Fourteen thousand one hundred seventy-eight participants
(8295 male, M
age
=36.70 SD =14.05) completed the study on the YourMorals.org
website. During registration participants completed the same ideology measure
described in Study 1a and in this sample consisted of 10,674 liberals, 1534 mod-
erates, and 1970 conservatives.
Procedure. Participants completed the Identification With All Humanity Scale40
that asks how much people identify with their community, their country, and the
world as a whole (e.g., “How much do you identify with (that is, feel a part of, feel
love toward, have concern for) each of the following?”People in my community,
people in my country, all humans everywhere). Participants used a 5-point scale
NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-12227-0 ARTICLE
NATURE COMMUNICATIONS | (2019) 10:4389 | https://doi.org/10.1038/s41467-019-12227-0 | www.nature.com/naturecommunications 9
Content courtesy of Springer Nature, terms of use apply. Rights reserved

(1 =not at all, 5 =very much) to answer nine questions for each of these entities—
community, country, and all humans—that assessed identification with each one.
We predicted that conservatism would predict identification with country, while
liberalism would predict identification with all humanity. We had no hypothesis
about identification with community.
Study 2a, participants. Four thousand four hundred and twenty-eight partici-
pants (2269 male, M
age
=36.56 SD =14.39) completed the study on the Your-
Morals.org website. Removing participants from analyses for which they were not
required (see below) did not change the primary pattern of the results. During
registration participants completed same ideology, age, gender, and education
measures described in Study 1a and this sample consisted of 3136 liberals, 592
moderates, and 700 conservatives.
Procedure. Participants began the task by reading the following instructions:
This is a study about pattern perception. On each of the next 30 screens,
you are going to see two boxes. (Do not worry, each screen takes just a few
seconds). In each box you will see some dots moving around. After 3 s,
three buttons will appear. Please click on the appropriate button to indicate
which box you like better. The buttons will disappear 5 s later, so you will
have to make your judgments within that 5 s period.
That may seem like an odd judgment to make, but if you just relax and let
yourself look back and forth between the two boxes, you will find yourself
having some slight feelings in response. You will find yourself liking one
box or the other a bit more. Do not think too much about the task, just go
with your feelings.
Next, they proceeded to evaluate 30 screens, in which two animations were
presented side by side (to view task access: http://yourmorals.org/dotspref_task.
php; see Supplementary Fig. 1 for depiction of task). Each animation consisted of
six dots that varied on two dimensions: (1) color diversity—all six dots were of the
same color (nondiverse) or of all different colors (diverse); (2) looseness-tightness
—the six dots either remained fixed as a single shape, a triangle (tight), moved
individually, but retained the general shape of a triangle (mobile), or orbited
around each other freely (loose). Animations were divided evenly into diverse and
nondiverse color patterns as well as tight or loose movement patterns, and were
randomly presented next to each other. After three seconds of the animation,
participants were asked to select one of three options: “I prefer this one”(presented
twice–once under each animation) or an option that said, “I have no preference at
all.”If participants did not select an option within 5 s, text appeared informing
participants they were too slow and asking them to try to click a button within 5 s
the next time. After the presentation of these 30 screens, participants answered a
question about how hard the task was and an open-ended question on what they
thought the purpose of the task was.
For each participant, preference for color diversity was computed by subtracting
the percentage preference for the nondiverse pattern from the percentage
preference for the diverse pattern. Preference for looseness was computed by
subtracting the percentage preference for the tight pattern from the combined
percentage preference for the loose and mobile patterns.
Animations such as these are often spontaneously anthropomorphized41,42, and
thus can be used as proxies for people’s perceptions of social ensembles.
Furthermore, this method is in line with recent work that has used basic schematics
and shapes to map low-level perceptual tendencies to meaningful political
ideological differences43,44.
Originally, this study was designed for a different purpose, to study the
relationship between political ideology and people’s feelings about superorganisms
(emergent social entities), with the prediction that liberals would prefer more
disordered ensembles, whereas conservatives would prefer more ordered
ensembles. This study also compared displays of heterogeneously colored versus
homogeneously colored ensembles, with the prediction that liberals would prefer
more diversely colored ensembles and conservatives would prefer uniformly
colored ensembles. Upon reexamining the study, we realized that it was relevant for
our purpose to test our hypotheses about ideological differences in preference for
moral circles of different types.
Study 2b, participants. Two thousand and seventy-four participants (997 male,
M
age
=34.87SD =13.96) completed the study on the YourMorals.org website.
Removing participants from analyses for which they were not required (see below)
did not change the primary pattern of results. During registration participants
completed the same ideology, age, gender, and education measures described in
Study 1a and in this sample consisted of 1468 liberals, 270 moderates, and 336
conservatives.
Procedure. The task participants perform was largely the same as in Study 2a
with a few notable exceptions (to view task access: http://yourmorals.org/
dotspref2_task.php; see Supplementary Fig. 2 for depiction of task): (1) Parti-
cipants viewed 12 screens rather than 30. (2) Diversity in color was not
manipulated (all the dots were the same color), but shape of the structure was
10 dots (rather than six in Study 2a) comprised the general shape of a triangle or
circle (3). Looseness-tightness was manipulated on two, rather than three levels
—thedotseitherremainedfixed as a single shape, a triangle or circle (tight),
or moved individually, but retained the general shape of a triangle or circle
(loose). Animations were divided evenly into circle and triangle shapes as well
as tight or loose movement patterns, and were randomly presented next to
each other.
For each participant, preference for shape was computed by subtracting the
percentage preference for the triangle shape from the percentage preference for the
circle shape. Preference for looseness was computed by subtracting the percentage
preference for the tight pattern from the percentage preference for the loose
pattern.
Like Study 2a, this study was initially designed to test the prediction that liberals
would prefer more disordered ensembles, whereas conservatives would prefer more
ordered ensembles. The prediction regarding shape was that liberals relative to
conservatives would prefer circles over triangles, manifesting a preference for
egalitarianism over hierarchy. As with Study 2a, upon reexamining this study, we
realized that it was relevant for our present hypotheses.
Study 3a, participants. One hundred thirty-one United States residents (53 male,
M
age
=35.82, SD =13.76) were recruited from the Amazon Mechanical Turk
(MTurk) marketplace for a small monetary reward. Although this sample size was
simply chosen on the basis of similar past studies, a post hoc power analysis
indicated that we had sufficient power (> 0.79) to detect the smallest correlation (in
absolute value) found in our analyses below (r=−0.24). Participants completed
the study using Qualtrics software, including an ideology measure that contained
seven options (very liberal, liberal, slightly liberal, moderate, slightly conservative,
conservative, very conservative). Participants were also asked about demographics
including age and gender (coded as in Study 1a) and education, which participants
were asked to enter in terms of years, with high school completion signifying 12.
For participants who entered a nonnumerical response, we translated their
response to a number using our best judgment (e.g., “some college”was translated
to 14 years). Our sample included 64 liberals, 31 moderates, and 36 conservatives,
and participants were only included in analyses if they completed the study in full.
Sample size was determined based on attempts to maximize statistical power and
was confined to participants who completed the study while it was available on the
MTurk marketplace.
Procedure. All participants completed a moral allocation task, in which partici-
pants allocated 100 “moral units”among the following 16 categories, pictured as
increasingly large concentric circles (see full depiction of task in Supplementary
Note 4): all of your immediate family; all of your extended family; all of your closest
friends; all friends including more distant friends; all acquaintances; all people
you have ever met; all people in your country; all people on your continent;
all people on all continents; all mammals on all continents; all
amphibians, reptiles, mammals, fish, and birds; all animals on earth including
paramecia and amoebae; all animals in the universe, including alien lifeforms; all
living things in the universe including plants and trees; all natural things in the
universe including inert entities such as rocks; all things in existence. Participants
read the following instructions:
In this section, we would like to think about your capacity to help, to give,
to be charitable, to show empathy, and to be generous—in other words,
your capacity to behave morally. We can think about people having
different amounts of moral units—like currency—that they can spend on
others and can allocate to different moral circles. Some people devote all of
their moral units to one circle whereas others try to divide up their moral
units amongst multiple circles. Again, by moral circle, we mean the circle of
people or other entities in which you are concerned about right and wrong
done toward them.
We also explained to participants that these categories were non-overlapping
such that giving to one category (e.g., extended family) would not include an
inclusive category (e.g., immediate family). Participants completed two iterations of
this task (order randomized). In one, they were asked to allocate moral units how
one should ideally divide them. In the other, they were asked to divide them as they
personally do so in their daily lives. These allowed us to assess differences between
actual and ideal moral allocation, but no meaningful differences emerged. The
categories allowed us to create composite moral allocation scores for humans only
(average of units allocated to the first nine categories) and for nonhumans (average
of units allocated to the last seven categories). In addition, participants also
completed a more qualitative measure of the extent of their moral circle by clicking
on rungs extending outward and representing the same categories as in the moral
allocation task (see Supplementary Note 4). This measure allowed us to create
heatmaps to visualize the relative sizes of liberals’and conservatives’moral circles.
This task was also counterbalanced in presentation with the moral allocation task,
and no order effects emerged.
Study 3b, participants. Two hundred sixty-three United States residents (173
male, M
age
=28.02, SD =9.13) were recruited from the Amazon Mechanical Turk
ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-12227-0
10 NATURE COMMUNICATIONS | (2019) 10:4389 | https://doi.org/10.1038/s41467-019-12227-0 | www.nature.com/naturecommunications
Content courtesy of Springer Nature, terms of use apply. Rights reserved

(MTurk) marketplace for a small monetary reward and completed the study using
Qualtrics software, including the same ideology, age, gender, and education mea-
sures used in Study 3a. Our sample included 176 liberals, 45 moderates, and 42
conservatives, and participants were only included in analyses if they completed the
study in full. Sample size was determined by attempting to double the sample size
of Study 3a, to ensure sufficient power.
Procedure. Participants completed the same personal moral allocation task as in
Study 3a, with one alteration. Participants were told that they could allocate any
amount to any group, and any amount overall. Participants varied greatly in
their total allocation of units to all categories, from 10 to 1053. Although we made
an a priori decision not to exclude outliers, all results described below remain
the same when excluding the one participant whose allocations fall outside of 3SD
of the mean. (We included this participant in analyses because our primary ana-
lyses involve proportions, which are constrained between 0 and 1 for all
participants.).
To analyze moral allocation to humans versus nonhumans, we computed a
proportion score for humans and nonhumans separately. To compute the human
allocation proportion score, we summed for each participant the nine categories
pertaining to humans exclusively and divided by the total units allocated to all
categories. To compute the nonhuman allocation proportion score, we summed for
each participant the seven categories pertaining to nonhumans and divided by the
total units allocated to all categories.
Reporting summary. Further information on research design is available in
the Nature Research Reporting Summary linked to this article.
Data availability
The datasets generated during and analyzed during this study are available from the
corresponding author on reasonable request. A reporting summary for this Article is
available as a Supplementary Information file.
Received: 8 October 2018 Accepted: 22 August 2019
References
1. Merry, M. W. Trump Vs. Hillary is nationalism vs. globalism, 2016. http://
nationalinterest.org/feature/trump-vs-hillary-nationalism-vs-globalism-2016-
16041 (2017).
2. Lawder, D. Bannon Departure tips trade scales in favor of White House
“Globalists”.https://www.reuters.com/article/us-usa-trump-trade-analysis/
bannon-departure-tips-trade-scales-in-favor-of-white-house-globalists-
idUSKCN1AY2IG (2017).
3. Ip, G. We are Not the World.https://www.wsj.com/articles/we-arent-the-
world-1483728161 (2017).
4. Singer, P. The Expanding Circle: Ethics and Sociobiology (Clarendon Press,
Oxford, UK, 1981).
5. Burke, E. Reflections on the Revolution in France (Dodsley, London, 1790).
6. Deutsch, M. Psychological roots of moral exclusion. J. Soc. Issues 46,21–25
(1990).
7. Opotow, S. Moral exclusion and injustice: an introduction. J. Soc. Issues 46,
1–20 (1990).
8. Turner, J. C., Hogg, M. A., Oakes, P. J., Reicher, S. D. & Wetherell, M. S.
Rediscovering the Social Group: A Self-categorization Theory (Basil Blackwell,
Oxford, UK, 1987).
9. Caprara, G. V. & Vecchione, M. On the left and right ideological divide:
historical accounts and contemporary perspectives. Polit. Psychol. 39,49–83
(2018).
10. Jost, J. T., Federico, C. M. & Napier, J. L. Political ideology: its
structure, functions, and elective affinities. Ann. Rev. Psychol. 60, 307–337
(2009).
11. Jost, J. T., Glaser, J., Kruglanski, A. W. & Sulloway, F. J. Political conservatism
as motivated social cognition. Psychol. Bull. 129, 339–375 (2003).
12. Jost, J. T. et al. Are needs to manage uncertainty and threat associated with
political conservatism or ideological extremity? Pers. Soc. Psychol. Bull. 33,
989–1007 (2007).
13. Carney, D. R., Jost, J. T., Gosling, S. D. & Potter, J. The secret lives of liberals
and conservatives: personality profiles, interaction styles, and the things they
leave behind. Polit. Psychol. 29, 807–840 (2008).
14. Haidt, J. & Joseph, C. Intuitive ethics: how innately prepared intuitions
generate culturally variable virtues. Daedalus 133,55–66 (2004).
15. Haidt, J. & Graham, J. When morality opposes justice: conservatives have
moral intuitions that liberals may not recognize. Soc. Just. Res. 20,98–116
(2007).
16. Graham, J., Haidt, J. & Nosek, B. A. Liberals and conservatives rely
on different sets of moral foundations. J. Pers. Soc. Psychol. 96, 1029–1046
(2009).
17. Crimston, D., Bain, P. G., Hornsey, M. J. & Bastian, B. Moral expansiveness:
examining variability in the extension of the moral world. J. Pers. Soc. Psychol.
111, 636–653 (2016).
18. Welzel, C. Freedom Rising: Human Empowerment and the Quest for
Emancipation (Cambridge University Press, Cambridge, 2013).
19. Hunter, J. D. Culture Wars: The Struggle to Define America (Basic Books, New
York, 1991).
20. Koleva, S. P. et al. Tracing the threads: How five moral concerns
(especially purity) help explain culture war attitudes. J. Res. Pers. 46, 184–194
(2012).
21. Hayes, A. F. Introduction to Mediation, Moderation, and Conditional Process
Analysis (The Guilford Press, New York, 2013).
22. Dhont, K. & Hodson, G. Why do right-wing adherents engage in more
animal exploitation and meat consumption? Pers. Indiv. Diff. 64,12–17
(2014).
23. Dhont, K., Hodson, G., Costello, K. & MacInnis, C. C. Social dominance
orientation connects prejudicial human–human and human–animal relations.
Pers. Indiv. Diff. 61, 105–108 (2014).
24. Bernhard, H., Fischbacher, U. & Fehr, E. Parochial altruism in humans.
Nature 442, 912–915 (2006).
25. De Dreu, C. K. et al. Reply to Chen et al.: perhaps goodwill is unlimited but
oxytocin-induced goodwill is not. Proc. Natl Acad. Sci. USA 108, E46–E46
(2011).
26. Galinsky, A. D., Maddux, W. W., Gilin, D. & White, J. B. Why it pays to get
inside the head of your opponent the differential effects of perspective taking
and empathy in negotiations. Psychol. Sci. 19, 378–384 (2008).
27. Haidt, J. The Righteous Mind: Why Good People are Divided by Politics and
Religion (Vintage Books, New York, 2012).
28. Sylwester, K. & Purver, M. Twitter language use reflects psychological
differences between democrats and republicans. PloS ONE 10, e0137422
(2015).
29. Alford, J. R., Funk, C. L. & Hibbing, J. R. Are political orientations genetically
transmitted? Am. Polit. Sci. Rev. 99, 153–167 (2005).
30. Block, J. & Block, J. H. Nursery school personality and political orientation
two decades later. J. Res. Pers. 40, 734–749 (2006).
31. Hibbing, J. R., Smith, K. B. & Alford, J. R. Differences in negativity bias
underlie variations in political ideology. Behav. Brain Sci. 37, 297–307
(2014).
32. Dodd, M. D. et al. The political left rolls with the good and the political right
confronts the bad: connecting physiology and cognition to preferences. Philos.
Trans. Roy. Soc. B. 367, 640–649 (2012).
33. Shook, N. J. & Fazio, R. H. Political ideology, exploration of novel stimuli, and
attitude formation. J. Exp. Soc. Psychol. 45, 995–998 (2009).
34. Iyer, R., Koleva, S., Graham, J., Ditto, P. & Haidt, J. Understanding libertarian
morality: the psychological dispositions of self-identified libertarians. PloS
ONE 7, e42366 (2012).
35. Gergen, K. J. Social psychology as history. J. Pers. Soc. Psychol. 26, 309–320
(1973).
36. Jost, J. T. The end of the end of ideology. Am. Psychol. 61, 651–670 (2006).
37. Graham, J., Waytz, A., Meindl, P., Iyer, R. & Young, L. Centripetal and
centrifugal forces in the moral circle: competing constraints on moral
learning. Cognition 167,58–65 (2017).
38. Campos, B., Keltner, D. & Gonzaga, G. C. Different KInds of Love: How Love
Experiences Differ Across Relationships (Poster presented at 2002 Western
Psychological Association, Irvine, California, 2002).
39. Schwartz, S. H. Universals in the content and structure of values: theoretical
advances and empirical tests in 20 countries. Adv. Exp. Soc. Psychol. 25,1–65
(1992).
40. McFarland, S. & Brown, D. Who believes that identification with all humanity
is ethical? Psicol. Polít. 36,37–49 (2008).
41. Heider, F. & Simmel, M. An experimental study of apparent behavior. Amer. J.
Psychol.57, 243–259 (1944).
42. Scholl, B. J. & Tremoulet, P. D. Perceptual causality and animacy. Trends
Cogn. Sci. 4, 299–309 (2000).
43. Kteily, N. S., Sheehy-Skeffington, J. & Ho, A. K. Hierarchy in the eye of the
beholder:(anti-) egalitarianism shapes perceived levels of social inequality. J.
Pers. Soc. Psychol. 112, 136–159 (2017).
44. Okimoto, T. G. & Gromet, D. M. Differences in sensitivity to deviance partly
explain ideological divides in social policy support. J. Pers. Soc. Psychol. 111,
98–117 (2016).
Author contributions
A.W., R.I., L.Y., J.H. and J.G.: all contributed to idea generation, methods, analysis, and
writing.
NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-12227-0 ARTICLE
NATURE COMMUNICATIONS | (2019) 10:4389 | https://doi.org/10.1038/s41467-019-12227-0 | www.nature.com/naturecommunications 11
Content courtesy of Springer Nature, terms of use apply. Rights reserved

Additional information
Supplementary Information accompanies this paper at https://doi.org/10.1038/s41467-
019-12227-0.
Competing interests: The authors declare no competing interests.
Reprints and permission information is available online at http://npg.nature.com/
reprintsandpermissions/
Peer review information Nature Communications thanks Brock Bastian and the other,
anonymous, reviewer(s) for their contribution to the peer review of this work.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in
published maps and institutional affiliations.
Open Access This article is licensed under a Creative Commons
Attribution 4.0 International License, which permits use, sharing,
adaptation, distribution and reproduction in any medium or format, as long as you give
appropriate credit to the original author(s) and the source, provide a link to the Creative
Commons license, and indicate if changes were made. The images or other third party
material in this article are included in the article’s Creative Commons license, unless
indicated otherwise in a credit line to the material. If material is not included in the
article’s Creative Commons license and your intended use is not permitted by statutory
regulation or exceeds the permitted use, you will need to obtain permission directly from
the copyright holder. To view a copy of this license, visit http://creativecommons.org/
licenses/by/4.0/.
© The Author(s) 2019
ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-12227-0
12 NATURE COMMUNICATIONS | (2019) 10:4389 | https://doi.org/10.1038/s41467-019-12227-0 | www.nature.com/naturecommunications
Content courtesy of Springer Nature, terms of use apply. Rights reserved

1.
2.
3.
4.
5.
6.
Terms and Conditions
Springer Nature journal content, brought to you courtesy of Springer Nature Customer Service Center GmbH (“Springer Nature”).
Springer Nature supports a reasonable amount of sharing of research papers by authors, subscribers and authorised users (“Users”), for small-
scale personal, non-commercial use provided that all copyright, trade and service marks and other proprietary notices are maintained. By
accessing, sharing, receiving or otherwise using the Springer Nature journal content you agree to these terms of use (“Terms”). For these
purposes, Springer Nature considers academic use (by researchers and students) to be non-commercial.
These Terms are supplementary and will apply in addition to any applicable website terms and conditions, a relevant site licence or a personal
subscription. These Terms will prevail over any conflict or ambiguity with regards to the relevant terms, a site licence or a personal subscription
(to the extent of the conflict or ambiguity only). For Creative Commons-licensed articles, the terms of the Creative Commons license used will
apply.
We collect and use personal data to provide access to the Springer Nature journal content. We may also use these personal data internally within
ResearchGate and Springer Nature and as agreed share it, in an anonymised way, for purposes of tracking, analysis and reporting. We will not
otherwise disclose your personal data outside the ResearchGate or the Springer Nature group of companies unless we have your permission as
detailed in the Privacy Policy.
While Users may use the Springer Nature journal content for small scale, personal non-commercial use, it is important to note that Users may
not:
use such content for the purpose of providing other users with access on a regular or large scale basis or as a means to circumvent access
control;
use such content where to do so would be considered a criminal or statutory offence in any jurisdiction, or gives rise to civil liability, or is
otherwise unlawful;
falsely or misleadingly imply or suggest endorsement, approval , sponsorship, or association unless explicitly agreed to by Springer Nature in
writing;
use bots or other automated methods to access the content or redirect messages
override any security feature or exclusionary protocol; or
share the content in order to create substitute for Springer Nature products or services or a systematic database of Springer Nature journal
content.
In line with the restriction against commercial use, Springer Nature does not permit the creation of a product or service that creates revenue,
royalties, rent or income from our content or its inclusion as part of a paid for service or for other commercial gain. Springer Nature journal
content cannot be used for inter-library loans and librarians may not upload Springer Nature journal content on a large scale into their, or any
other, institutional repository.
These terms of use are reviewed regularly and may be amended at any time. Springer Nature is not obligated to publish any information or
content on this website and may remove it or features or functionality at our sole discretion, at any time with or without notice. Springer Nature
may revoke this licence to you at any time and remove access to any copies of the Springer Nature journal content which have been saved.
To the fullest extent permitted by law, Springer Nature makes no warranties, representations or guarantees to Users, either express or implied
with respect to the Springer nature journal content and all parties disclaim and waive any implied warranties or warranties imposed by law,
including merchantability or fitness for any particular purpose.
Please note that these rights do not automatically extend to content, data or other material published by Springer Nature that may be licensed
from third parties.
If you would like to use or distribute our Springer Nature journal content to a wider audience or on a regular basis or in any other manner not
expressly permitted by these Terms, please contact Springer Nature at
onlineservice@springernature.com