Religiosity and intelligence

Religiousness and intelligence is a subject of studies on the social correlates of intelligence and IQ. Other studies focus on correlations between religiosity and other socioeconomic factors typically associated with intelligence, such as higher education and interest in science. Such studies are often controversial, especially among the public, and critics in these areas examine the validity and fairness of cognitive testing, as well as the definition of others measurements under discussion, in this case religiousness. Many of the issues pertaining to the investigation of group differences in intelligence vis-à-vis religiousness are also raised in the investigation of race and intelligence&mdash;a better established, though even more controversial, area of intelligence research.

Older studies
In 1986, the magazine Sceptic summarized studies on religiousness and intelligence: All but four of the forty-three polls listed support the conclusion that native intelligence varies inversely with degree of religious faith; i.e., that, other factors being equal, the more intelligent a person is, the less religious he is.

In this essay: Some examples from this overview:
 * Conclusions
 * 1) sixteen studies of the correlation between individual measures of student intelligence and religiosity, all but three of which reported an inverse correlation.
 * 2) five studies reporting that student bodies with high average IQ and/or SAT scores are much less religious than inferior student bodies;
 * 3) three studies reporting that geniuses (IQ 150+) are much less religious than the general public (Average IQ, 100), and one dubious study;
 * 4) seven studies reporting that highly successful persons are much less religious in belief than are others; and
 * 5) eight old and four new Gallup polls revealing that college alumni (average IQ about 115) are much less religious in belief than are grade-school pollees.

One study of a group with IQ's over 140 found that of men, 10 percent held strong religious belief, of women 18 percent (Terman, 1959). 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."

A study of Mensa members found that they had much fewer religious beliefs than the typical American college alumnus or adult (Southern and Plant, 1968). It is not clear whether Mensa members are representative of high-IQ people in this regard.

Students attending higher-ranked schools have fewer religious beliefs than those attending lower-ranked schools (Caplovitz and Sherrow, 1977). (It should be noted, however, that the ranking of schools is a highly debated issue, and most highly-ranked schools in this survey came from states that were generally less religious.)

Five of these studies concerned how liberal or conservative a person's religious views were, as opposed to whether a person was or was not religious in the first place. For example, Unitarians were up to 81.4 times overrepresented in higher education, according to one of the studies, and Quakers are traditionally overrepresented in the sciences.

Recent studies
In Explorations: An undergraduate research journal, Regan Clarke reports religious belief and behavior were negatively correlated with SAT scores in the USA. In 2000, noted skeptic Michael Shermer found a negative correlation between education and religosity in the United States, though Rice University indicates this may not apply to the social sciences.

Several studies on Americans focus on the beliefs of high-IQ individuals. In one study, 90% of the general population surveyed professed a distinct belief in a personal god and afterlife, while only 40% of the scientists with a BS surveyed did so, and only 10% of those considered "eminent.". Another study found that mathematicians were just over 40%, biologists just under 30%, and physicists were barely over 20% likely to believe in God.

A survey of members of the United States National Academy of Sciences showed that 72% are outright atheists, 21% are agnostic and only 7% admit to belief in a personal God.

The Pew Global Attitudes Project surveyed opinions by nation with the question "How important is religion in your life—very important, somewhat important, not too important, or not at all important?" The report finds that Americans are much more religious than people living in other wealthy nations. In the U.S., 59% of people reported religion was "very important", as compared to 30% in Canada. In this way, the views of Americans are more simliar to people in developing countries than those in developed countries. The study found a correlation between the percentage of people reporting that religion was "very important" and the national per-capita GDP. It can be further stated that the nations who scored as most religious tended to have low science scores according to TIMSS. Also an inverse correlation at Nationmaster can be found between mathematical literacy and church attendance. (Although labor regulation and police per capita were far stronger inverse correlations) No significant inverse correlation showed up for scientific literacy or reading literacy however.

Criticism
As the IQ or other standarized test is used to measure intelligence, those who question the IQ test will not consider valid to use it for searching correlations with other variables (see IQ for further discussion).

Some of the studies primarily deal with unmarried high-school and university students, and other studies show people become more religious after marriage and children. A recent Gallup International survey indicates this is international. It showed that levels of atheism decline after age 30 while self-description as "a religious person" rises.

Published studies of religiousness and intelligence have been predominantly performed in the US, which has a much higher level of religiosity than other developed nations.. See Atheism for more statistics on this.