Fact: Intelligent people tend to be more secular.
Summary
The broad consensus of research shows that people with higher IQs tend to be less religious, not more so.
Argument
Is it more logical to be a Christian? Is religion the natural choice of a smart person familiar with more of the evidence? Not according to a broad consensus of studies on IQ and religiosity. These studies have consistently found that the lower the IQ score, the more likely a person is to be religious.
To place these studies in perspective, it is helpful to know the general religious attitudes of Americans today. According to a February 1995 Gallup poll, 96 percent of all Americans believe in God, and 88 percent affirm the importance of religion. However, the degree of religiosity within this group varies considerably. Only 35 percent can be classified as "religious," using a definition that requires them to consider religion important and attend religious services at least once a week. And a March 1994 Gallup poll found that only 20 percent of all Americans belong to that politically active group known as "Christian conservatives."
The following is a review of several studies of IQ and religiosity, paraphrased and summarized from Burnham Beckwith's article, "The Effect of Intelligence on Religious Faith," Free Inquiry, Spring 1986: (1)
STUDIES OF STUDENTS
1. Thomas Howells, 1927
Study of 461 students showed religiously conservative students "are, in general, relatively inferior in intellectual ability."
2. Hilding Carlsojn, 1933
Study of 215 students showed that "there is a tendency for the more intelligent undergraduate to be sympathetic toward… atheism."
3. Abraham Franzblau, 1934
Confirming Howells and Carlson, tested 354 Jewish children, aged 10-16. Found a negative correlation between religiosity and IQ as measured by the Terman intelligence test.
4. Thomas Symington, 1935
Tested 400 young people in colleges and church groups. He reported, "There is a constant positive relation in all the groups between liberal religious thinking and mental ability… There is also a constant positive relation between liberal scores and intelligence…"
5. Vernon Jones, 1938
Tested 381 students, concluding "a slight tendency for intelligence and liberal attitudes to go together."
6. A. R. Gilliland, 1940
At variance with all other studies, found "little or no relationship between intelligence and attitude toward god."
7. Donald Gragg, 1942
Reported an inverse correlation between 100 ACE freshman test scores and Thurstone "reality of god" scores.
8. Brown and Love, 1951
At the University of Denver, tested 613 male and female students. The mean test scores of non-believers was 119 points, and for believers it was 100. The non-believers ranked in the 80th percentile, and believers in the 50th. Their findings "strongly corroborate those of Howells."
9. Michael Argyle, 1958
Concluded that "although intelligent children grasp religious concepts earlier, they are also the first to doubt the truth of religion, and intelligent students are much less likely to accept orthodox beliefs."
10. Jeffrey Hadden, 1963
Found no correlation between intelligence and grades. This was an anomalous finding, since GPA corresponds closely with intelligence. Other factors may have influenced the results at the University of Wisconsin.
11. Young, Dustin and Holtzman, 1966
Average religiosity decreased as GPA rose.
12. James Trent, 1967
Polled 1400 college seniors. Found little difference, but high-ability students in his sample group were over-represented.
13. C. Plant and E. Minium, 1967
The more intelligent students were less religious, both before entering college and after 2 years of college.
14. Robert Wuthnow, 1978
Of 532 students, 37 percent of Christians, 58 percent of apostates, and 53 percent of non-religious scored above average on SATs.
15. Hastings and Hoge, 1967, 1974
Polled 200 college students and found no significant correlations.
16. Norman Poythress, 1975
Mean SATs for strongly antireligious (1148), moderately anti-religious (1119), slightly antireligious (1108), and religious (1022).
17. Wiebe and Fleck, 1980
Studied 158 male and female Canadian university students. They reported "nonreligious S's tended to be strongly intelligent" and "more intelligent than religious S's."
STUDENT BODY COMPARISONS
1. Rose Goldsen, 1952
Percentage of students who believe in a divine god: Harvard 30; UCLA 32; Dartmouth 35; Yale 36; Cornell 42; Wayne 43; Weslyan 43; Michigan 45; Fisk 60; Texas 62; North Carolina 68.
2. National Review Study, 1970
Percentage of students who believe in a Spirit or Divine God: Reed 15; Brandeis 25; Sarah Lawrence 28; Williams 36; Stanford 41; Boston U. 41; Yale 42; Howard 47; Indiana 57; Davidson 59; S. Carolina 65; Marquette 77.
3. Caplovitz and Sherrow, 1977
Apostasy rates rose continuously from 5 percent in "low" ranked schools to 17 percent in "high" ranked schools.
4. Niemi, Ross, and Alexander, 1978
In elite schools, organized religion was judged important by only 26 percent of their students, compared with 44 percent of all students.
STUDIES OF VERY-HIGH IQ GROUPS
1. Terman, 1959
Studied group with IQ's over 140. Of men, 10 percent held strong religious belief, of women 18 percent. Sixty-two percent of men and 57 percent of women claimed "little religious inclination" while 28 percent of the men and 23 percent of the women claimed it was "not at all important."
2. Warren and Heist, 1960
Found no differences among National Merit Scholars. Results may have been effected by the fact that NM scholars are not selected on the basis of intelligence or grades alone, but also on "leadership" and such like.
3. Southern and Plant, 1968
Studied 42 male and 30 female members of Mensa. Mensa members were much less religious in belief than the typical American college alumnus or adult.
STUDIES Of SCIENTISTS
1. William S. Ament, 1927
C. C. Little, president of the University of Michigan, checked persons listed in Who's Who in America: "Unitarians, Episcopalians, Congregationalists, Universalists, and Presbyterians [who are less religious] are… far more numerous in Who's Who than would be expected on the basis of the population which they form. Baptists, Methodists, and Catholics are distinctly less numerous."
Ament confirmed Little's conclusion. He noted that Unitarians, the least religious, were more than 40 times as numerous in Who's Who as in the U.S. population.
2. Lehman and Witty, 1931
Identified 1189 scientists found in both Who's Who (1927) and American Men of Science (1927). Only 25 percent of those listed in the latter and 50 percent of those in the former reported their religious denomination, despite the specific request to do so, under the heading of "religious denomination (if any)." Well over 90 percent of the general population claims religious affiliation. The figure of 25 percent suggests far less religiosity among scientists.
Unitarians were 81.4 times as numerous among eminent scientists as non-Unitarians.
3. Kelley and Fisk, 1951
Found a negative (-.39) correlation between the strength of religious values and research competence. [How these were measured is unknown.]
4. Ann Roe, 1953
Interviewed 64 "eminent scientists, nearly all members of the prestigious National Academy of Sciences or the American Philosophical Society. She reported that, while nearly all of them had religious parents and had attended Sunday school, 'now only three of these men are seriously active in church. A few others attend upon occasion, or even give some financial support to a church which they do not attend… All the others have long since dismissed religion as any guide to them, and the church plays no part in their lives… A few are militantly atheistic, but most are just not interested.'"
5. Francis Bello, 1954
Interviewed or questionnaired 107 nonindustrial scientists under the age of 40 judged by senior colleagues to be outstanding. Of the 87 responses, 45 percent claimed to be "agnostic or atheistic" and an additional 22 percent claimed no religious affiliation. For 20 most eminent, "the proportion who are now a-religious is considerably higher than in the entire survey group."
6. Jack Chambers, 1964
Questionnaired 740 US psychologists and chemists. He reported, "The highly creative men… significantly more often show either no preference for a particular religion or little or no interest in religion." Found that the most eminent psychologists showed 40 percent no preference, 16 percent for the most eminent chemists.
7. Vaughan, Smith, and Sjoberg, 1965
Polled 850 US physicists, zoologists, chemical engineers, and geologists listed in American Men of Science (1955) on church membership, and attendance patterns, and belief in afterlife. Of the 642 replies, 38.5 percent did not believe in an afterlife, whereas 31.8 percent did. Belief in immortality was less common among major university staff than among those employed by business, government, or minor universities. The Gallup poll taken about this time showed that two-thirds of the U.S. population believed in an afterlife, so scientists were far less religious than the typical adult.
Conclusion
The consensus here is clear: more intelligent people tend not to believe in religion. And this observation is given added force when you consider that the above studies span a broad range of time, subjects and methodologies, and yet arrive at the same conclusion.
This is the result even when the researchers are Christian conservatives themselves. One such researcher is George Gallup. Here are the results of a Fall 1995 Gallup poll:
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