Politics and Religion (2022), 15, 827–840
doi:10.1017/S1755048322000104
NOTE
A Short Scale for Measuring Political Secularism*
Kai Arzheimer
JGU University of Mainz
Address correspondence and reprint requests to: Kai Arzheimer, Department of Political Science, JGU
University of Mainz, Mainz, Germany. E-mail: arzheimer@politik.uni-mainz.de
Abstract
As religiousness is declining across democracies, scientific interest in secular orientations
and their political implications is growing. One specific and particularly important aspect
of secular attitudes is political secularism. Political secularism is not merely the absence of
religiousness, but rather a world view which holds that religious beliefs should play no role
in politics. While there are hundreds of survey instruments that measure the strength and
content of religiousness, there is no comparable measure that taps into political secular-
ism. In this research note, I briefly review the concept of political secularism and present
a cluster of items which target it. Utilizing data from four large population representative
samples taken from the eastern and western states of Germany, I use confirmatory factor
analysis to show that these items form a short but internally consistent scale. This scale
also displays convergent and discriminant validity. It may be readily used in future
surveys.
Introduction
Social scientists have long been aware that religion is a powerful political force and
that by implication, significant changes to the religious makeup of a society will
have far-reaching political repercussions. The growing number of people who identify
as Muslims is one such change that has become a hot button issue in Europe.
However, Muslims currently make up just 5% of Europe’s population, and even
under a high immigration/high fertility scenario, their share will rise to less than
15% over the next three decades (Pew Research Center 2017). At least numerically,
secularization is a much more important development in Europe.
Secularization is a multi-faceted term which denotes both social and intrapersonal
processes (Sommerville 1998) that diminish the role of religion at the societal, group,
and individual levels (Stolz and Tanner 2019, 2). At the micro-level, applied research
usefully distinguishes between a decline in membership and practice on the one hand
and a decline in individual beliefs on the other. The former may outpace the latter,
*I gratefully acknowledge financial support from Deutsche Forschungsgemeinschaft/German Research
Foundation for the collection of the PRDB data (grant number AR 369/5).
© The Author(s), 2022. Published by Cambridge University Press on behalf of Religion and Politics Section of the
American Political Science Association. This is an Open Access article, distributed under the terms of the Creative
Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribu-
tion and reproduction, provided the original article is properly cited.
https://doi.org/10.1017/S1755048322000104 Published online by Cambridge University Press
828 Kai Arzheimer
creating “unchurched” segments of the population that still believe but no longer
belong (Davie 1990). However, in their global survey of religious life, Norris and
Inglehart (2011) demonstrate that in some parts of the world and most notably in
Western Europe, both membership and belief have been on the retreat for decades.
These trends continue to the present day, making Western Europe “one of the world’s
most secular regions” where “many do not describe themselves as Christian” (Pew
Research Center 2018, 6).
For many of these citizens (in Europe and elsewhere), being secular is not just the
absence of religion: they embrace secularism as a non-religious world-view. In the
broadest possible sense, secularism is an idea that “seeks to restrict religious elements”
(Stolz and Tanner 2019). While such an outlook has multiple dimensions, one par-
ticularly interesting one is political secularism, a preference to limit religion’s role in
politics (Beard et al. 2013).
One prominent account (Voas 2009) of religious change in Europe that is well
supported by empirical data holds that long-running societal secularization brings
about individual secularism, via a mechanism of changing socialization patterns
and generational replacement. At the same time, individual (political) secularism
may lead to demand for policy changes (e.g., full legal recognition of same-sex part-
nerships) that in turn drive further societal secularization. Somewhat paradoxically,
secularization in Europe is also contributing to a re-politicization of religion: it
makes societies more culturally diverse and results in polarization between religious
organizations and citizens on the one hand and their political secular opponents on
the other (Pickel 2017).
To gauge the importance of these issues at the micro-level, a survey measure for
political secularism is required. Yet, although there is a plethora of scales for measur-
ing religiousness, secularism as such is rarely studied, and not a single psychometri-
cally evaluated instrument for measuring politically secular attitudes exists.
In this research note, I briefly review the concept of political secularism and pre-
sent a cluster of items which target it. Using data from four large population repre-
sentative samples, I show that these items form a short, internally consistent scale,
and that this scale also displays convergent and discriminant validity.
What is Political Secularism, and How can it be Measured?
Rates of religious membership and participation have been a concern for social sci-
entists since the inception of sociology in the 19th century. Attempts to complement
them by instruments that capture more private religious practice as well as the struc-
ture of religious beliefs and attitudes hark back to at least the 1950s. Allport and
Ross’s distinction between intrinsic and extrinsic orientations (Allport and Ross
1967) is perhaps the most famous example of this early research. Less than two
decades later, Gorsuch (1984) reviewed the many instruments already existing at
the time and strongly argued against their further proliferation. Yet after another
quarter-century, Cutting and Walsh (2008) counted nearly 180 scales for measuring
religiousness, and their number is still growing.
Almost all of these scales implicitly follow Sommerville’s classic notion that secular
attitudes represent a “shift of attention from ultimate (religious) concerns to proximate
https://doi.org/10.1017/S1755048322000104 Published online by Cambridge University Press
Politics and Religion 829
concerns” (Sommerville 1998, 250), i.e., a lapse from or a neglect of religion. While such
“passive secularism” is an important phenomenon in itself, “active secularism,” i.e., “the
affirmation of secular identity and beliefs” (Campbell et al. 2018, 553) is arguably a more
interesting cluster of attitudes. While passively secular citizens are by definition indiffer-
ent toward religion but may still accept its traditional role in society and politics, actively
secular citizens are positively opposed to religious arguments and authority, which may
spur them into political activity and lead them to adopt more extreme positions (see,
e.g., Layman and Weaver 2016; Brockway 2018; Layman et al. 2021).
Just like religion, secularism has several “dimensions” (Campbell et al. 2018) or
“facets” (Beard et al. 2013). These include philosophical convictions, social values,
secular identities, and negative emotions toward religious authority and doctrine,
all of which can have political consequences.
In a narrower sense, political secularism refers to one’s attitudes on “the proper
role of religious beliefs in political life” (Beard et al. 2013, 758). More succinctly, polit-
ical secularism holds that religious beliefs should not be used to justify curbing indi-
vidual freedoms, and should play little, if any role in political debates.
As a political and legal idea, political secularism is well-researched (Bhargava 2008;
Cliteur and Ellian 2020). However, there is not one validated scale for political secu-
larism at the micro-level. This is problematic, because politically secular views are
believed to become more and more widespread in Europe and even in the United
States, and because they represent a particularly disruptive type of active secularism.
This is because they are conceptually linked to a host of polarizing “morality policies,”
which pit religious views and actors against notions of individual freedom (Mourão
Permoser 2019). If one wants to assess the alleged spread of politically secular views as
well as their impact on politics, it is therefore desirable to have an instrument that is
both reliable and valid and preferably comprises multiple indicators.
However, even single-item questions or short batteries that tap into politically sec-
ular views are rare in the extant literature. Beard et al. (2013), who prominently make
the case for researching political secularism at the micro-level, propose only two items
that fit their own definition: “Do you worry the government is getting too involved in
the issue of morality?” and “Should churches and other houses of worship keep out of
political matters” (Beard et al. 2013, 760).1
Brockway (2018), in his useful study of “committed seculars,” relies on a single
item that refers to one important but very specific aspect of political secularism,
namely the separation of church and state. Similarly, Castle (2015) measures opinions
on “religious establishment” using an index comprising four items that refer to gov-
ernment institutions and officials engaging in and supporting religious activities.
Finally, Ribberink et al. (2018) measure “anti-religiosity” by combining four items
that were included in the 1998 and 2008 waves of the International Social Survey
Programme (ISSP). Two of these items refer to respondents’ views of believers and
their creeds as intolerant and belligerent. Such opinions may be secular, but they are
not politically secular in the aforementioned sense. The two other items tap into attitudes
on the role of religious leaders in politics. These items are a better fit for the concept of
political secularism but again address a single, rather narrow and specific aspect of it.
Conversely, a valid and reliable scale for measuring political secularism should
consist of several items that cover the breadth of the relationship between religion
https://doi.org/10.1017/S1755048322000104 Published online by Cambridge University Press
830 Kai Arzheimer
and politics. While developing such a scale from scratch would have its own obvious
benefits, re-using existing items from large-scale surveys has at least three important
advantages. First, it is already clear that these items “work” in surveys of the general
public. Second, replicating single items or group of items opens up the possibility of
meaningful comparisons between new and existing surveys. Third, if a whole set of
items is replicated that form a scale, its reliability and validity can be assessed across
different settings.
The questionnaire of an older survey (“Church and Religion in an enlarged
Europe” (CREE)), which ran in 2006 in various European countries and targeted atti-
tudes on “religion, society, and life in general” (Pollack et al. 2007, 20), provides a
useful starting point. Its large pool of questions contains five items that closely fit
Beard et al.’s (2013) definition of political secularism.
One of these items (Symbols, see below) was taken from the earlier “Religious and
Moral Pluralism” survey. Another one (Debates) came from the ISSP survey series
and is one of the two that were also used by Ribberink et al. (2018). The remaining
three were written by members of the CREE team.2
These five (and also some of the other) items were then subsequently included in
the 2012 iteration of Germany’s biannual General Social Survey (ALLBUS) in some-
what modified form:
(1) “The EU treaties should contain a reference to the Christian god” (God EU)
(reversed)
(2) “Religious symbols such as crucifixes should be banned from state schools”
(Symbols)
(3) “Education in state schools should be free of religious elements” (Education)
(4) “Scientific research on humans should not be limited by religious norms and
values” (Science)
(5) “Religious norms and values have no place in public debates on political
issues” (Debates)
When the “Problems of Representation in the Domain of Biopolitics” (PRDB)
project set out in 2016 to measure political secularism and its effects at the micro-
level, it adopted these five items for its nationally representative survey. For compa-
rability with the ALLBUS and because the rewritten items are even better suited for
measuring political secularism, the PRDB project also used the new wording.3
The PRDB project chose these items because collectively, they capture different
aspects of political secularism as defined by Beard et al. (2013). The first question
was highly controversial in European Union politics in the 2000s and is still useful
as a supranational variation of the classic question about the separation of church
and state. The second and third items relate to the role of religion in state schools,
which is another contentious issue for secularists in many societies. The fourth
item alludes to the role of religious authority in one specific domain of regulatory pol-
itics where appeals to religious doctrine are frequent. More generally, it also taps into
secular support for science and rationality. Finally, the fifth item spells out the core
tenet of political secularism: that religion should play no role in politics.
https://doi.org/10.1017/S1755048322000104 Published online by Cambridge University Press
Politics and Religion 831
Data
The analyses presented in the remainder of this research note are based on data from
the 2012 ALLBUS round (GESIS—Leibniz-Institut für Sozialwissenschaften 2019)
and the 2016 PRDB survey (Arzheimer 2016). Both datasets are available in their
entirety from Germany’s national data archive, where they can be located by following
their respective DOIs.
Because of the persistent political, social, and economic east-west differences
within Germany, both studies drew separate and disproportionately large samples
of respondents from Germany’s eastern states. For the present research question,
this is particularly apt because West German politics was dominated for decades
by a Christian Democratic party, whereas Eastern Germany was a self-avowed irreli-
gious state. As a consequence of this research design, the analyses are effectively based
on four large (n = 740–2,538), independent samples.
While the ALLBUS usually uses an odd (five, seven, or eleven) number of catego-
ries for measuring agreement, they retained the CREE’s original four-point format.
Conversely, the PRDB survey employed five categories with a neutral mid-point for
almost all items and adjusted the items’ response options accordingly. Otherwise,
the wording of the items is identical across the samples.
Reliability and Dimensionality
Methods
Any presumptive scale must be internally consistent, i.e., its items should tap into a
single common dimension. Internal consistency is one important type of reliability,
which in turn is a necessary but insufficient condition for validity. Traditionally,
internal consistency is assessed by calculating Cronbach’s alpha (Cronbach 1951),
which can be interpreted as the mean of all possible split-half reliabilities across a
given set of items.
Confirmatory factor analysis (CFA) provides a complementary perspective that is
more nuanced and can also help mitigate some of the well-known problems4 linked
to the exclusive reliance on alpha (Viladrich et al. 2017). However, the common prac-
tice of establishing unidimensionality mechanically by assessing the fit of a single-
factor model may also be misleading, because established fit indices as well as
newer measures may be too sensitive to trivial violations under some circumstances
while failing to identify clearly multidimensional structures in others (Reise et al.
2013). Therefore, a detailed inspection of the measurement model that takes into
account not just various fit indices and newer variations of alpha but also the factor
loadings and possibly alternative specifications of the measurement model is required.
One final complexity arises from the ordinal nature of the survey responses. While
items with as few as five categories are sometimes treated as if they were continuous
(Viladrich et al. 2017), the WLSMV estimator, which was specifically developed for
large samples of ordinal measurements, was employed for both surveys. Therefore,
the factor loadings are probit coefficients, and variants of alpha that account for
the ordinal nature of the data (Green and Yang 2009) were calculated. Threshold
parameters are omitted from the main tables but documented in the Appendix.
https://doi.org/10.1017/S1755048322000104 Published online by Cambridge University Press
832 Kai Arzheimer
Table 1. Measurement of political secularism by five items (factor loadings only)
West 2016 East 2016 West 2012 East 2012
Loading: Symbols 0.68*** 0.77*** 0.63*** 0.71***
(0.02) (0.02) (0.02) (0.02)
Loading: Science 0.60*** 0.52*** 0.51*** 0.64***
(0.02) (0.03) (0.02) (0.02)
Loading: Education 0.75*** 0.83*** 0.76*** 0.81***
(0.02) (0.02) (0.02) (0.02)
Loading: Debates 0.67*** 0.76*** 0.55*** 0.66***
(0.02) (0.02) (0.02) (0.02)
Loading: God EU 0.59*** 0.66*** 0.43*** 0.49***
(0.03) (0.03) (0.02) (0.03)
Observations 1,269 739 2,334 1,121
CFI 0.92 0.97 0.95 0.99
TLI 0.84 0.94 0.89 0.99
RMSEA 0.18 0.14 0.11 0.05
SRMR 0.05 0.03 0.03 0.01
Parameters 25 25 20 20
Ordinal α 0.78 0.83 0.70 0.79
Ordinal ω3 (ρNL) 0.81 0.85 0.73 0.81
***p < 0.001; **p < 0.01; *p < 0.05. Threshold parameters are omitted from the table for better legibility. Full set of
parameters are given in the Appendix.
Findings
Table 1 shows the estimates for a preliminary measurement model for political sec-
ularism. All five items display substantial factor loadings in the correct direction.
(Ordinal) alpha varies between 0.7 and 0.83, a range that is usually seen as acceptable
to good. Because the measurement model assumes that the items are congeneric
whereas alpha presupposes tau-equivalent items, (ordinal) omega is a more appropri-
ate measure of internal consistency (Viladrich et al. 2017). The respective row in
Table 1 shows that values for omega are indeed slightly higher, but the differences
are minuscule.
The evidence from the fit indices, however, is more mixed. The CFI and the SRMR
show an acceptable fit in all four samples. Conversely, the TLI and the RMSEA indi-
cate that the model fit is unsatisfactory for all respondents but those interviewed in
the east in 2012.
A closer look at the bivariate correlations reveals that there is a particularly close
relationship between the two items referring to the role of religion in state schools,
which can be explained by their very similar content. This in turn suggests that allow-
ing their error variances to correlate could improve the model fit substantially.
https://doi.org/10.1017/S1755048322000104 Published online by Cambridge University Press
Politics and Religion 833
Table 2. Measurement of political secularism by four items (factor loadings only)
West 2016 East 2016 West 2012 East 2012
Loading: Science 0.67*** 0.56*** 0.54 *** 0.64 ***
(0.02) (0.03) (0.02) (0.03)
Loading: Education 0.59 *** 0.72 *** 0.63 *** 0.76 ***
(0.02) (0.03) (0.02) (0.03)
Loading: Debates 0.75 *** 0.84 *** 0.67 *** 0.70 ***
(0.02) (0.02) (0.02) (0.02)
Loading: God EU 0.59 *** 0.66 *** 0.42 *** 0.50 ***
(0.03) (0.03) (0.02) (0.03)
Observations 1,269 739 2,330 1,121
CFI 1.00 0.99 0.99 1.00
TLI 1.00 0.96 0.96 1.00
RMSEA 0.02 0.11 0.07 0.00
SRMR 0.01 0.02 0.02 0.00
Parameters 20 20 16 16
Ordinal α 0.74 0.79 0.65 0.74
Ordinal ω3 (ρNL) 0.74 0.84 0.66 0.75
***p < 0.001; **p < 0.01; *p < 0.05. Threshold parameters are omitted from the table for better legibility. Full set of
parameters are given in the Appendix.
From a substantive point of view, however, it is preferable to remove the Symbols item
from the scale. First, having two items that refer to public education gives disproportion-
ate weight to this specific aspect of political secularism. Second, while both items are
similar, “religious elements” is more general and already encompasses “religious sym-
bols.” Third, the meaning of the former item is also clearer, because almost all federal
states provide some form of religious education in state schools, whereas crucifixes in
schools (and other public buildings) are closely linked to the Bavarian Christian
Democrats (CSU) and their representation of Bavarian identity. Moreover, because “reli-
gious symbols” also include the hijab, they item may also tap into anti-Muslim senti-
ment. And finally, short(er) scales have clear advantages: they often provide a more
realistic assessment of reliability, increase the motivation of and decrease the burden
on respondents, and are cheaper to administer (Gogol et al. 2014).
Table 2 shows the estimates for the four-item measurement model. The factor load-
ings remain high, and their direction is still correct. Omega and alpha are somewhat
lower, which is expected because they partly depend on the number of items, but still
acceptable. Finally, the CFI, TLI, and SRMR indicate near perfect fit in all four samples.
The RMSEA indicates a very good fit for all samples but the eastern one in 2016.
Taken together, these findings suggest that the four items form a consistent scale
that works reasonably well across slightly different formats (four versus five scale
points) and cultural settings (Germany’s staunchly secular eastern states versus the
https://doi.org/10.1017/S1755048322000104 Published online by Cambridge University Press
834 Kai Arzheimer
more religiously diverse states in the west). The next section will assess the question
whether the scale is also valid.
Validity
Many different types of validity have been proposed in the literature. However, they
all relate to the same underlying question: to what degree does an instrument tap into
what it is supposed to measure? Thus, they should be seen as “tests” that provide
(sometimes conflicting) evidence on the question of validity, which “can never be
answered with absolute certainty” (Bollen 1989, 185).
This uncertainty is fundamental: in an ideal world, validity could be quantified
simply by the correlation of a scale with some universally accepted external criterion,
but in reality, there is usually no such gold standard. Like reliability, validity is there-
fore best investigated making use of CFA, which opens up many sophisticated possi-
bilities (see, e.g., O’Leary-Kelly and Vokurka 1998).
In this section, I follow a comparatively simple approach (see, e.g., Hayes et al.
2005, 309): I demonstrate that scores on the secularism scale are highly correlated
with measurements that they should correlate with (convergent validity), yet remain
distinguishable from them (discriminant validity). This provides a more rounded
view of the scale’s validity than the relationship with a single criterion and is a
first step toward a full nomological validation, which would test a whole network
of theoretical propositions and auxiliary assumptions (see, e.g., Hagger et al. 2017).
There are two constructs available across the four samples that can be used for val-
idation, one rather specific, the other more general.
Attitudes on a specific policy, namely legal access to abortion, form the first of
these constructs. The regulation of abortion is widely seen as one of the most prom-
inent “morality issues” (Mooney and Schuldt 2008; Studlar et al. 2013) worldwide.
Efforts to limit legal access to abortions are almost universally spearheaded by reli-
gious organizations, who explicitly claim that they act on of their beliefs. This suggests
that political secularism should be positively associated with more permissive views
on abortion. However, because this is a single specific policy, because many other fac-
tors may shape one’s views on abortion, and because the items used in the surveys
make no reference to religious doctrine, this correlation should be far from perfect.
All surveys include four identical or very similar items on the regulation of abor-
tion (see the Appendix for details). A preliminary analysis shows that all items display
substantial loadings on the common factor. Ordinal alpha is high and ordinal omega
is acceptable across all four samples so that the construct may be used for validation.
The second, more general construct is a composite measure of religiousness that
encompasses individual and collective religious practice on the one hand (prayer
and attendance) and self-conception as more or less religious on the other. All
three items display substantial loadings on the common factor. Alpha is high, and
omega is acceptable across all four samples (see the Appendix for details).
Following Beard et al. (2013), I have argued above that political secularism should
not be understood as the absence of religiousness but rather as an attitude on the
proper role of religion in political life. For the validity of the political secularism
scale, its correlation with religiousness is therefore crucial. Overall, a strong negative
https://doi.org/10.1017/S1755048322000104 Published online by Cambridge University Press
Politics and Religion 835
relationship is to be expected: non-religious citizens should be opposed to religious
interference in the public sphere, whereas believers should support institutional
arrangements that make outcomes which align with their beliefs more likely.
Having said that, many religious citizens (particularly in some protestant traditions)
may still favor a clear separation of church and state. Conversely, lukewarm believers
and even non-believers may see a societal value in religion. Political secularism and
religiousness should hence remain distinguishable.
To investigate the validity of the secularism scale, a joint model of secularism and atti-
tudes on abortion was estimated (see the tables in Appendix for the full results). Table 3
shows that the two-factor model, which treat secularism and abortion attitudes as sepa-
rate constructs, fit the data very well. In line with expectations, the correlation between the
factors is clearly positive (more secular respondents do indeed have more permissive
views on legal access to abortion) but far from perfect, with values between 0.35 and 0.53.
Conversely, assuming that all items load on a single common factor results in a
dramatic decline of model fit to values that would be unacceptable by common stan-
dards. This provides some initial evidence for the convergent and discriminant valid-
ity of the secularism scale.
In the next step, a joint model for secularism and religiousness was estimated (see
the tables in the Appendix for the full results). Table 4 shows that a two-factor sol-
ution again achieves an acceptable fit across all four samples.5 In line with expecta-
tions, the estimated correlation between secularism and religiousness is negative
and quite substantial, with values ranging from −0.56 to −0.70.
To ascertain that political secularism and religiousness are indeed closely related
but not identical, again all items were forced to load on a single common factor.
Once more this results in a dramatic increase in χ2 and a decline in all measures
of model fit well below the common cut-off criteria.
Taken together, these findings already provide strong evidence for the convergent
and discriminant validity of the political secularism scale. Ideally, they should be
complemented by a full nomological validation in future research.
Conclusion
Recent research highlights the importance of political secularism as an individual atti-
tude that affects political behavior. While secularism as a political and philosophical
concept has existed for centuries and while there is a plethora of measures for indi-
vidual religiousness, there is no established instrument for measuring political secu-
larism at the micro-level.
In this research note, I introduce a cluster of items which tap into individual polit-
ical secularism. Applying CFA, I show that these items form an internally consistent
scale. Importantly, good internal consistency can be achieved with just four items.
Such short scales are becoming increasingly popular, because they reduce both sur-
veys costs and the burden on respondents.
The secularism scale also displays a moderate to strong positive correlation with
permissive views on abortion and a strongly negative correlation with religiousness,
yet it remains clearly distinguishable from both. This suggests that the scale is not
just a reliable but also a valid instrument for measuring political secularism.
https://doi.org/10.1017/S1755048322000104 Published online by Cambridge University Press
836 Kai Arzheimer
https://doi.org/10.1017/S1755048322000104 Published online by Cambridge University Press
Table 3. Secularism and abortion attitudes
West 2016 East 2016 West 2012 East 2012
Two factors One factor Two factors One factor Two factors One factor Two factors One factor
ϕ 0.46 *** 0.53 *** 0.45 *** 0.35 ***
(0.04) (0.06) (0.03) (0.05)
Observations 1,269 1,269 740 740 2,354 2,354 1,122 1,122
CFI 0.98 0.85 0.97 0.83 0.96 0.82 0.99 0.85
TLI 0.97 0.79 0.96 0.76 0.95 0.74 0.99 0.79
RMSEA 0.05 0.13 0.05 0.12 0.05 0.11 0.03 0.11
SRMR 0.04 0.12 0.05 0.12 0.05 0.11 0.05 0.16
χ2 71.93 473.07 52.67 240.40 128.39 574.54 34.07 274.75
Parameters 29 28 29 28 25 24 25 24
***p < 0.001; **p < 0.01; *p < 0.05.
Politics and Religion 837
https://doi.org/10.1017/S1755048322000104 Published online by Cambridge University Press
Table 4. Secularism and religiousness
West 2016 East 2016 West 2012 East 2012
Two factors One factor Two factors One factor Two factors One factor Two factors One factor
ϕ −0.70 *** −0.67 *** −0.70 *** −0.56 ***
(0.02) (0.03) (0.02) (0.03)
Observations 1,269 1,269 740 740 2,357 2,357 1,122 1,122
CFI 0.96 0.85 0.97 0.79 0.92 0.80 0.95 0.71
TLI 0.94 0.77 0.94 0.68 0.86 0.71 0.92 0.56
RMSEA 0.07 0.13 0.07 0.17 0.08 0.12 0.07 0.17
SRMR 0.03 0.06 0.02 0.08 0.03 0.06 0.03 0.10
χ2 86.19 310.44 59.70 305.69 228.41 515.70 90.60 472.31
Parameters 30 29 30 29 26 25 26 25
***p < 0.001; **p < 0.01; *p < 0.05.
838 Kai Arzheimer
However, there are some limitations. First, the analyses presented in this note rely
on surveys that were carried out in Germany only, albeit both in the territory of the
former Federal Republic of Germany and the former German Democratic Republic.
In future research, they should be complemented by comparative survey data to ascer-
tain that measurements are invariant (Davidov 2009) across cultural, political, and
linguistic borders. Ideally, they would be included in large-scale projects such as
the European Social Survey.
Second, and relatedly, the item referencing the European Union (EU) treaties should
obviously be confined to the EUs 27 member states. In an even broader context, it
would have to be adapted, e.g., by instead referring to the national constitution.6
Third, while internal consistency is a central aspect of the scale’s reliability, it is
unrelated to test–retest reliability (McCrae et al. 2011). Political secularism itself
should be a relatively stable attitude. If the scale is reliable, measurements of secular-
ism should be relatively stable, too, at least in the short and medium term. Ideally,
future surveys should therefore administer the items repeatedly so that we may
learn more about the scale’s properties.
But ultimately, the usefulness of the scale can only be gauged in applied research:
including the scale in rich and substantively interesting models of political attitudes
and behavior will yield the true test of nomological validation.
Supplementary material. The supplementary material for this article can be found at https://doi.org/10.
1017/S1755048322000104.
Data. Replication data and scripts for this article are available from the author’s dataverse: https://doi.org/
10.7910/DVN/XEKNYW
Notes
1. A third item (“Do religious beliefs most influence your thinking about government and public affairs?”)
is more a matter of self-perception than a statement about the desired role of religion in public life.
2. Personal communication with Olaf Müller, one of the former CREE project members.
3. The Debates item originally more specifically referred to “religious leaders” trying to influence public
debate. Because the new wording is more general, it better captures political secularism. Other modifica-
tions are very minor.
4. Alpha can be misleading if the items are not tau-equivalent or if the structure of the underlying mea-
surement model is not simple. In its original formulation, it is also not adequate if measurements are ordi-
nal. Finally, striving for a particularly high value of alpha during scale development may lead to the
inclusion of redundant indicators, because alpha is also a function of the number of items.
5. For the West German sample from 2012, the TLI is below the usual cut-off value of 0.95, but the other
indices still suggest a reasonable fit.
6. The CREE project used this variation of the item in Russia.
References
Allport GW and Ross JM (1967) “Personal Religious Orientation and Prejudice.” Journal of Personality
and Social Psychology 5, 432–443.
Arzheimer K (2016) “Problems of Representation in the Domain of Biopolitics (PRDB)—Einstellungen Zur
Präimplantationsdiagnostik.” DOI: https://doi.org/10.7802/2028
Beard TR, Ekelund RB, Ford GS, Gaskins B and Tollison RD, (2013) “Secularism, Religion, and Political
Choice in the United States.” Politics and Religion 6, 753–777.
https://doi.org/10.1017/S1755048322000104 Published online by Cambridge University Press
Politics and Religion 839
Bhargava R (2008) “Political Secularism, eds. Dryzek JS, Honig B and Phillips A (eds), The Oxford
Handbook of Political Theory. Oxford: Oxford University Press, online publication. DOI: https://doi.
org/10.1093/oxfordhb/9780199548439.003.0035.
Bollen KA (1989) “Structural Equations with Latent Variables.” New York: Wiley.
Brockway M (2018) “Home on Sunday, Home on Tuesday? Secular Political Participation in the United
States.” Politics and Religion 11, 334–363.
Bumpass LL (1997) “The Measurement of Public Opinion on Abortion: The Effects of Survey Design.”
Family Planning Perspectives 29, 177.
Campbell DE, Layman GC, Green JC and Sumaktoyo NG (2018) “Putting Politics First: The Impact of
Politics on American Religious and Secular Orientations.” American Journal of Political Science 62, 551–565.
Castle JJ (2015) “The Electoral Impact of Public Opinion on Religious Establishment.” Journal for the
Scientific Study of Religion 54, 814–832.
Cliteur P and Ellian A (2020) “The Five Models for State and Religion: Atheism, Theocracy, State Church,
Multiculturalism, and Secularism.” ICL Journal 14, 103–132.
Cronbach LJ (1951) “Coefficient Alpha and the Internal Structure of Tests.” Psychometrika 16, 297–334.
Cutting M and Walsh M (2008) “Religiosity Scales: What Are We Measuring in Whom?” Archive for the
Psychology of Religion/Archiv Für Religionpsychologie 30. Review of scales, 137–154.
Davidov E (2009) “Measurement Equivalence of Nationalism and Constructive Patriotism in the ISSP: 34
Countries in a Comparative Perspective.” Political Analysis 17, 64–82.
Davie G (1990) “Believing without Belonging: Is this the Future of Religion in Britain?” Social Compass 37,
455–469.
GESIS—Leibniz-Institut für Sozialwissenschaften (2019). “German General Social Survey—ALLBUS
2012/German General Social Survey—ALLBUS 2012.” DOI: https://doi.org/10.4232/1.13418
Gogol K, Brunner M, Goetz T, Martin R, Ugen S, Keller U, Fischbach A and Preckel F (2014) “‘My
Questionnaire Is Too Long!’ The Assessments of Motivational-Affective Constructs with Three-Item and
Single-Item Measures.” Contemporary Educational Psychology 39, 188–205.
Gorsuch RL (1984) “Measurement: The Boon and Bane of Investigating Religion.” American Psychologist
39, 228–236.
Green SB and Yang Y (2009) “Reliability of Summed Item Scores Using Structural Equation Modeling: An
Alternative to Coefficient Alpha.” Psychometrika 74, 155–167.
Hagger MS, Gucciardi DF and Chatzisarantis NLD (2017) “On Nomological Validity and Auxiliary
Assumptions: The Importance of Simultaneously Testing Effects in Social Cognitive Theories Applied
to Health Behavior and Some Guidelines.” Frontiers in Psychology 8, 1933.
Hayes AF, Glynn CJ and Shanahan J (2005) “Willingness to Self-Censor: A Construct and Measurement
Tool for Public Opinion Research.” International Journal of Public Opinion Research 17, 298–323.
Layman GC, Campbell DE, Green JC and Sumaktoyo NG (2021) “Secularism and American Political
Behavior.” Public Opinion Quarterly 85, 79–100.
Layman GC and Weaver CL (2016) “Religion and Secularism among American Party Activists.” Politics
and Religion 9, 271–295.
McCrae RR, Kurtz JE, Yamagata S and Terracciano A (2011) “Internal Consistency, Retest Reliability,
and Their Implications for Personality Scale Validity.” Personality and Social Psychology Review 15,
28–50.
Mooney CZ and Schuldt RG (2008) “Does Morality Policy Exist? Testing a Basic Assumption.” Policy
Studies Journal 36, 199–218.
Mourão Permoser J (2019) “What are Morality Policies? The Politics of Values in a Post-Secular World.”
Political Studies Review 17, 310–325.
Norris P and Inglehart R (2011) Sacred and Secular. Religion and Politics Worldwide, 2nd Edn.
Cambridge: Cambridge University Press.
O’Leary-Kelly SW and Vokurka RJ (1998) The Empirical Assessment of Construct Validity. Journal of
Operations Management 16, 387–405.
Pew Research Center (2017) “Europe’s Growing Muslim Population.” Pew Research Center. Available at
https://www.pewforum.org/wp-content/uploads/sites/7/2017/11/FULL-REPORT-FOR-WEB-POSTING.pdf.
Pew Research Center (2018) “Being Christian in Western Europe.” Pew Research Center. Available at
https://www.pewforum.org/wp-content/uploads/sites/7/2018/05/Being-Christian-in-Western-Europe-
FOR-WEB1.pdf.
https://doi.org/10.1017/S1755048322000104 Published online by Cambridge University Press
840 Kai Arzheimer
Pickel G (2017) “Secularization—An Empirically Consolidated Narrative in the Face of an Increasing
Influence of Religion on Politics.” Política & Sociedade 16, 259–294.
Pollack D, Pickel G and Müller O (2007). Church and Religion in an Enlarged Europe (C&R 2006).
Cumulated Codebook. Frankfurt/Oder: European University Viadrina/Chair for Comparative
Sociology of Culture. Available at https://www.uni-muenster.de/imperia/md/content/soziologie/per-
sonen/pollack/church_religion_codebuch.pdf.
Reise SP, et al. (2013) “Multidimensionality and Structural Coefficient Bias in Structural Equation
Modeling.” Educational and Psychological Measurement 73, 5–26.
Ribberink E, Achterberg P and Houtman D (2018) “Religious Polarization: Contesting Religion in
Secularized Western European Countries.” Journal of Contemporary Religion 33, 209–227.
Sommerville CJ (1998) “Secular Society/Religious Population: Our Tacit Rules for Using the Term
‘Secularization’.” Journal for the Scientific Study of Religion 37, 249–253.
Stolz J and Tanner P (2019) “Secularization, Secularity, and Secularism in the New Millennium:
Macro-Theories and Research.” In: Oxford Research Encyclopedia of Politics. Oxford University Press.
DOI: https://doi.org/10.1093/acrefore/9780190228637.013.792
Studlar DT, Cagossi A and Duval RD (2013) “Is Morality Policy Different? Institutional Explanations for
Post-War Western Europe.” Journal of European Public Policy 20, 353–371.
Viladrich C, Angulo-Brunet A and Doval E (2017) “A Journey Around Alpha and Omega to Estimate
Internal Consistency Reliability.” Anales de Psicologïa 33, 755–782.
Voas D (2009) “The Rise and Fall of Fuzzy Fidelity in Europe.” European Sociological Review 25, 155–168.
Kai Arzheimer is professor of German politics and political sociology at the University of Mainz
(Germany). He has published widely in political behavior and electoral politics.
Cite this article: Arzheimer K (2022). A Short Scale for Measuring Political Secularism. Politics and
Religion 15, 827–840. https://doi.org/10.1017/S1755048322000104
https://doi.org/10.1017/S1755048322000104 Published online by Cambridge University Press