Public Acceptance of Evolution

Full text

www.sciencemag.org SCIENCE VOL 313 11 AUGUST 2006
765
POLICYFORUM
T
he concept of the evolution of humans
from earlier forms of life is unaccept-
able to biblical literalists and causes
concern even among some holders of less
conservative religious views. Catholics and
mainstream Protestants generally accept vari-
ations of a theological view known as theistic
evolution, which views evolution as the means
by which God brought about humans, as well
as other organisms. Evolution is nonetheless
problematic to some of these nonliteralist
Christians, because it implies a more distant
or less personal God (1–3). Efforts to insert
“intelligent design” into school science cur-
ricula seek to retain the divine design of
humans while remaining agnostic on earlier
creationist beliefs in a young Earth and the
coexistence of humans and dinosaurs (2, 4).
Beginning in 1985, national samples of
U.S. adults have been asked whether the
statement, “Human beings, as we know
them, developed from earlier species of ani-
mals,” is true or false, or whether the respon-
dent is not sure or does not know. We com-
pared the results of these surveys with survey
data from nine European countries in 2002,
surveys in 32 European countries in 2005,
and a national survey in Japan in 2001 (5).
Over the past 20 years, the percentage of U.S.
adults accepting the idea of evolution has
declined from 45% to 40% and the percent-
age of adults overtly rejecting evolution
declined from 48% to 39%. The percentage
of adults who were not sure about evolution
increased from 7% in 1985 to 21% in 2005.
After 20 years of public debate, the public
appears to be divided evenly in terms of
accepting or rejecting evolution, with about
one in five adults still undecided or unaware
of the issue. This pattern is consistent with a
number of sporadic national newspaper sur-
veys reported in recent years (6–10).
A dichotomous true-false question format
tends to exaggerate the strength of both posi-
tions. In 1993 and 2003, national samples of
American adults were asked about the same
statement but were offered the choice of say-
ing that the statement was “definitely true,
probably true, probably false, definitely
false,” or that they did not know or were uncer-
tain. About a third of American adults firmly
rejected evolution, and only 14% of adults
thought that evolution is “definitely true.”
Treating the “probably” and “not sure” cate-
gories as varying degrees of uncertainty,
~55% of American adults have held a tentative
view about evolution for the last decade.
This pattern is different from that seen in
Europe and Japan. Looking first at the simpler
true-false question, our analysis found that
significantly (at the 0.01 to 0.05 level by dif-
ference of proportions) (11) more adults in
Japan and 32 European countries accepted the
concept of evolution than did American adults
(see figure, right). Only Turkish adults were
less likely to accept the concept of evolution
than American adults. In Iceland, Denmark,
Sweden, and France, 80% or more of adults
accepted the concept of evolution, as did 78%
of Japanese adults.
A cross-national study of the United States
and nine European nations in
2002–2003 used the expanded ver-
sion of the question. The results
confirm that a significantly lower
proportion of American adults
believe that evolution is absolutely
true than adults in nine European
countries [see fig. S1 in the Sup-
porting Online Material (SOM)].
A third of American adults indi-
cated that evolution is “absolutely
false”; the proportion of Euro-
pean adults who thought that
evolution was absolutely false
ranged from 7% in Denmark,
France, and Great Britain to 15%
in the Netherlands.
Regardless of the form of the
question, one in three American
adults firmly rejects the concept
of evolution, a significantly higher
proportion than found in any
western European country. How
can we account for this pattern of
American reservations about the
concept of evolution in the
context of broad acceptance in
Europe and Japan?
First, the structure and beliefs
of American fundamentalism his-
torically differ from those of main-
stream Protestantism in both the
United States and Europe. The biblical literal-
ist focus of fundamentalism in the United
States sees Genesis as a true and accurate
account of the creation of human life that
supersedes any scientific finding or interpre-
tation. In contrast, mainstream Protestant
faiths in Europe (and their U.S. counterparts)
have viewed Genesis as metaphorical and—
like the Catholic Church—have not seen a
major contradiction between their faith and
the work of Darwin and other scientists.
To test this hypothesis empirically, a two-
group structural equation model (SEM) (12,
13) was constructed using data from the
United States and nine European countries
(see statistical analyses in SOM). The SEM
allows an examination of the relation between
several variables simultaneously on one or
more outcome variables. In this model, 10
independent variables—age, gender, educa-
tion, genetic literacy, religious belief, attitude
toward life, attitude toward science and tech-
The acceptance of evolution is lower in the
United States than in Japan or Europe, largely
because of widespread fundamentalism and the
politicization of science in the United States.
Public Acceptance of Evolution
Jon D. Miller,
1
* Eugenie C. Scott,
2
Shinji Okamoto
3
SCIENCE COMMUNICATION
1
Michigan State University, East Lansing, MI 48824–1115,
USA.
2
National Center for Science Education, Oakland, CA
94609, USA.
3
Kobe University, Rokkaido, Hyogo, Japan.
*Author for correspondence. E-mail: jdmiller@msu.edu
United Kingdom (1308)
Iceland (n = 500)
Denmark (1013)
Sweden (1023)
France (1021)
Japan (2146)
Norway (976)
Belgium (1024)
Spain (1035)
Germany (1507)
Italy (1006)
Netherlands (1005)
Hungary (1000)
Luxembourg (518)
Ireland (1008)
Slovenia (1061)
Finland (1006)
Czech Republic (1037)
Estonia (1000)
Portugal (1009)
Malta (500)
Switzerland (999)
Slovak Republic (1241)
Poland (999)
Austria (1034)
Croatia (1000)
Romania (1005)
Greece (1000)
Bulgaria (1008)
Lithuania (1003)
Latvia (1034)
Cyprus (505)
United States (1484)
Turkey (1005)
0 20 40
Response
60 80 100
FalseTrue Not sure
Public acceptance of evolution in 34 countries, 2005.
Published by AAAS

766
nology (S&T), belief in S&T, reservations
about S&T, and political ideology—were
used to predict attitude toward evolution. The
total effect of fundamentalist religious beliefs
on attitude toward evolution (using a stan-
dardized metric) was nearly twice as much in
the United States as in the nine European
countries (path coefficients of –0.42 and
–0.24, respectively), which indicates that
individuals who hold a strong belief in a per-
sonal God and who pray frequently were sig-
nificantly less likely to view evolution as
probably or definitely true than adults with
less conservative religious views.
Second, the evolution issue has been
politicized and incorporated into the current
partisan division in the United States in a
manner never seen in Europe or Japan. In the
second half of the 20th century, the conserva-
tive wing of the Republican Party has adopted
creationism as a part of a platform designed
to consolidate their support in southern and
Midwestern states—the “red” states. In the
1990s, the state Republican platforms in
seven states included explicit demands for the
teaching of “creation science” (1). There is
no major political party in Europe or Japan
that uses opposition to evolution as a part of
its political platform.
The same SEM model discussed above
offers empirical support for this conclusion.
In the United States, the abortion issue has
been politicized and has become a key wedge
issue that differentiates conservatives and
liberals. In the SEM, individuals who held
strong pro-life beliefs were significantly
more likely to reject evolution than individ-
uals with pro-choice views. The total effect
of pro-life attitudes on the acceptance of
evolution was much greater in the United
States than in the nine European coun-
tries (–0.31 and –0.09, respectively) [see
Statistical Analyses section of Supporting
Online Material].
The same model also documents the link-
age of religious conservative beliefs and a
conservative partisan view in the United
States. The path coefficient for the relation
between fundamentalist religious views and
self-identification as a conservative was 0.26
in the United States and 0.17 in the nine
European countries. The path coefficient
between pro-life views and self-identifica-
tion as a conservative was 0.20 in the United
States and 0.06 in the nine European coun-
tries. Because the two-group SEM com-
putes path coefficients on a common met-
ric, these results are directly comparable
and the impact of fundamentalist religious
beliefs and pro-life attitudes may be seen as
additive (12, 13).
Third, genetic literacy has a moderate
positive relationship to the acceptance of
evolution in both the United States and the
nine European countries. This result indi-
cates that those adults who have acquired
some understanding of modern genetics are
more likely to hold positive attitudes toward
evolution. The total effect of genetic liter-
acy on the acceptance of evolution was
similar in the United States and the nine
European countries.
Although the mean score on the Index of
Genetic Literacy was slightly higher in the
United States than the nine European coun-
tries combined, results from another 2005
U.S. study show that substantial numbers of
American adults are confused about some
of the core ideas related to 20th- and 21st-
century biology. When presented with a
description of natural selection that omits
the word evolution, 78% of adults agreed to
a description of the evolution of plants and
animals (see table S2 in SOM). But, 62% of
adults in the same study believed that God
created humans as whole persons without
any evolutionary development.
It appears that many of these adults have
adopted a human exceptionalism perspec-
tive. Elements of this perspective can be
seen in the way that many adults try to inte-
grate modern genetics into their under-
standing of life. For example, only a third
of American adults agree that more than
half of human genes are identical to those
of mice and only 38% of adults recognize
that humans have more than half of their
genes in common with chimpanzees. In
other studies (1, 14, 15), fewer than half of
American adults can provide a minimal
definition of DNA. Thus, it is not surpris-
ing that nearly half of the respondents in
2005 were not sure about the proportion of
human genes that overlap with mice or
chimpanzees.
These results should be troubling for sci-
ence educators at all levels. Basic concepts
of evolution should be taught in middle
school, high school, and college life sci-
ences courses and the growing number of
adults who are uncertain about these ideas
suggests that current science instruction is
not effective. Because of the rapidly emerg-
ing nature of biomedical science, most
adults will find it necessary to learn about
these new concepts through informal learn-
ing opportunities (15–17). The level of
adult awareness of genetic concepts (a
median score of 4 on a 0-to-10 scale) sug-
gests that many adults are not well informed
about these matters. The results of the SEM
indicate that genetic literacy is one impor-
tant component that predicts adult accept-
ance of evolution.
The politicization of science in the name
of religion and political partisanship is not
new to the United States, but transformation
of traditional geographically and economi-
cally based political parties into religiously
oriented ideological coalitions marks the
beginning of a new era for science policy. The
broad public acceptance of the benefits of sci-
ence and technology in the second half of the
20th century allowed science to develop a
nonpartisan identification that largely pro-
tected it from overt partisanship. That era
appears to have closed.
References and Notes
1. F. R. A. Paterson, L. F. Rossow, Am. Biol. Teach. 61(5),
358 (1999).
2. E. C. Scott, Evolution vs. Creationism (Greenwood Press,
Westport, CT, 2004).
3. S. M. Barr, First Things Monthly J. Relig. Public Life 156,
9 (2005).
4. Tammy Kitzmiller et al. v. Dover Area School District et
al., 2005 WL 578974 (MD Pa. 2005), 20 December
2005.
5. Materials and methods are available as supporting mate-
rial on Science Online.
6. Harris poll no. 52, “Nearly two-thirds of U.S. adults
believe human beings were created by God” (Harris
Interactive, New York, 6 July 2005).
7. Scripps Howard News Service, Evolution poll results, 15
November 2005
(www.knoxstudio.com/shns/story.cfm?pk=EVOLUTION-
CHART1-11-15-05&cat=AN).
8. NBC News poll, 8 to 10 March 2005
(www.pollingreport.com/science.htm).
9. CBS News/New York Times poll, 18 to 21 November 2004
(www.pollingreport.com/science.htm).
10. Gallup poll, 7 to 10 November 2004 (www.polling-
report.com/science.htm).
11. H. M. Blalock, Social Statistics (McGraw-Hill, New York,
1960).
12. L. A. Hayduk, Structural Equation Modeling with LISREL
(Johns Hopkins Univ. Press, Baltimore, 1987).
13. K. Jöreskog, D. Sörbom, LISREL 8 (Scientific Software
International, Chicago, 1993).
14. J. D. Miller, R. Pardo, F. Niwa, Public Perceptions of
Science and Technology: A Comparative Study of the
European Union, the United States, Japan, and Canada
(BBV Foundation Press, Madrid, 1997).
15. J. D. Miller, L. G. Kimmel, Biomedical Communications
(Academic Press, New York, 2001).
16. J. D. Miller, Sci. Commun. 22(3), 256 (2001).
17. J. D. Miller, in Free-Choice Science Education, J. H. Falk,
Ed. (Teachers College Press, New York, 2001), pp.
93–114.
18. Supported by the U.S. National Science Foundation (NSF
grants SRS88-07409, SRS90-02467, SRS92-17876,
SRS99-06416, ESI-0201155, and ESI-0206184);
ScienCentral, Inc.; Foundation BBVA; the Commission of
the European Union; and the National Institute of
Science and Technology Policy (NISTEP) in Japan. R.
Pardo, director general of the Foundation BBVA, was
responsible for the design and direction of the 2002
European biotechnology study, and we are deeply appre-
ciative of his leadership and scholarship in this regard.
All conclusions are the responsibility of the authors and
do not necessarily reflect the views of the any funding
organization or the staff of any funding organization.
Supporting Online Material
www.sciencemag.org/cgi/content/full/313/5789/765/DC1
10.1126/science.1126746
11 AUGUST 2006 VOL 313 SCIENCE www.sciencemag.org
POLICYFORUM
Published by AAAS