Elsevier

Intelligence

Volume 37, Issue 1, January–February 2009, Pages 81-93
Intelligence

The intelligence–religiosity nexus: A representative study of white adolescent Americans

https://doi.org/10.1016/j.intell.2008.08.003Get rights and content

Abstract

The present study examined whether IQ relates systematically to denomination and income within the framework of the g nexus, using representative data from the National Longitudinal Study of Youth (NLSY97). Atheists score 1.95 IQ points higher than Agnostics, 3.82 points higher than Liberal persuasions, and 5.89 IQ points higher than Dogmatic persuasions. Denominations differ significantly in IQ and income. Religiosity declines between ages 12 to 17. It is suggested that IQ makes an individual likely to gravitate toward a denomination and level of achievement that best fit his or hers particular level of cognitive complexity. Ontogenetically speaking this means that contemporary denominations are rank ordered by largely hereditary variations in brain efficiency (i.e. IQ). In terms of evolution, modern Atheists are reacting rationally to cognitive and emotional challenges, whereas Liberals and, in particular Dogmatics, still rely on ancient, pre-rational, supernatural and wishful thinking.

Introduction

Charles Spearman (1904) made a discovery a century ago about human cognition so fundamental that it approaches the status of a law of nature: Individuals who perform well (or badly) in one area of cognition tend to perform well (or badly) in all other, even rather dissimilar, cognitive areas. The practical implication of this principle is difficult to underestimate: For example, top performers in mathematics can be expected to do well not only in classical languages, but also in pitch discrimination, memory, and general problem solving irrespective of topic. Being a pioneer also in early factor analysis Spearman extracted two factors from the sub-test correlations matrix, one of which he designated general intelligence, g. Another major achievement is Arthur Jensen's further refinement of Spearman's original g measure (e.g. Jensen, 1998). Among other things, Jensen verified that the g factor is not merely a mathematical artifact, but “… a single dimension of individual differences that cuts across a variety of learning tasks (Jensen, 1998 p. 95).

Research on g can be ordered along a vertical axis (the causal basis for g) and a horizontal axis (its practical or predictive value), according to Jensen (1998, p. 95).

Vertically speaking, the g factor is a physiological phenomenon with multiple biological correlates (Jensen, 1998, Chapter 6; Jensen & Sinha, 1993). It is heritable, but heritabilities range from a rather low .20 in early childhood to an impressive .80 in late adulthood (e.g. Plomin and Spinath, 2004, Polderman et al., 2006). It appears that the full expression of genetic g is observed only later in life, after the individual has had a chance to actively realize its full potential. Because factor g is a phenotypic indicator of neural brain efficiency (Jensen, 1998), it comes as no surprise that recent brain research shows that g correlates positively with the size of about 10 small gray matter brain areas and intelligence (e.g. Jung & Haier, 2007). As could be expected, also brain size is largely inherited (Pennington et al., 2000, Toga and Thompson, 2005). The vertical evidence for g testifies to Spearman's original vision that g will only be fully understood in terms of “… the most profound and detailed direct study of the human brain in its purely physical and chemical aspects” (Spearman, 1927, p. 403), and a program — called physicology — has been formulated to further promote such an approach (Nyborg, 1994, Nyborg, 1997, Nyborg, 2007a).

Horizontally speaking, the broad practical significance of g emanates “… from the fact it is causally related to many real-life conditions, both personal and social. All these relationships form a complex correlational network, or nexus, in which g is the major node” (Jensen, 1998, p. 544). Jensen is careful to point out that individual and group differences in g specify only the essential minimum level needed for achievement in areas like education, occupation, and economy, and that many non-g specific abilities, talents, personality, social and pure chance factors may help co-determine individual and group outcome. A large number of studies nevertheless show that g is the single most important predictor variable for individual and group differences in such diverse areas as employment, health, poverty, crime, welfare and, recently, cross-national student performance and national wealth (e.g. Batty et al., 2007, Gottfredson, 1997, Herrnstein and Murray, 1994, Lynn and Vanhanen, 2002, Nyborg, 2007b, Rindermann, 2007).

The purpose of the present article is to bring religiosity within the g nexus. There are good reasons for this. First, despite centuries of research and discussion we still do not know how to best account for the origin, development and persistence of religion worldwide. Second, religiosity occupies many people — almost everybody in developmental countries, but also a majority in developed societies (Zuckerman, 2006). The latter observation is puzzling, because religiosity is basically incompatible with a modern rational or scientific understanding. Religiosity thus refers to 1) beliefs, ranging from souls, invisible worlds, supernatural Gods or forces, to angels, devils, and holy spirits, and 2) claims about supernatural forces that control our behavior, feeling and thinking. To be sure, the various denominations differ considerably in intensity, direction and the nature of their beliefs and claims, but they all have supernatural phenomena in common, and this certainly goes far beyond rational explanation and objectivity. The intelligence–religiosity contrast becomes even more obvious in the following brief review of previous research that brings religiosity within the scope of the g nexus framework.

Section snippets

Selective historical review

The scriptures contain references to intelligence. For example Proverb (3:7, Scripture, 1982) states: “Trust in the Lord with all your heart, and lean not on your own understanding. In all your ways acknowledge Him, and He shall direct your paths. Do not be wise in your own eyes. Fear the Lord”. Even more to the point: “Blessed are the poor in spirit: for theirs is the kingdom of heaven.” (Matthew 5:3 in King James Bible).

The research literature on intelligence and religiosity is rather

The present study

The problem with many older studies on intelligence–religiosity connections is that they typically draw on convenience sampling and make ad hoc interpretation. Often they remain purely descriptive or sociological at heart, and rarely do they consider the outcome within a testable empirical paradigm. This raised a need for extending the deductive framework of the g nexus to cover bonds between intelligence and type of religious persuasion. Ontogenetic and evolutionary aspects are also missing

Computer adaptive testing

The CAT-ASVAB97 consists of the ten power and two speeded sub-tests shown in Table 1.

The U.S. Department of Defense developed a computer adaptive form for the 10 power sub-tests, so that the testing procedure “… matches the difficulty level of the individual test items to the ability levels of the respondents” (details in Owen, 1969, Owen, 1975, Segall et al., 1997). The two speeded tests in the CAT-ASVAB, Coding Speed and Numerical Operations were administered in a non-adaptive format, that

Results

Syllogism 1 (high-IQ people gravitate towards atheism and/or science, and low-IQ people remain religious) was tested in an ANOVA design with IQ as dependent factor and Atheist versus religious as the categorical variable. Agnostics were left out of this analysis, as they could neither be classified as atheists nor religious.

Table 3 confirms that white religious people trail Atheists by 5.13 IQ points. Analysis of variance on the actual number of respondents indicates that this difference is

Discussion

All six predictions came true. Syllogism 1 (Table 3) was confirmed when believers were found to trail Atheists by 5.13 IQ points. This dovetails well with the literature review that the most eminent, and by proxy most intelligent, scientists are Atheists; more than 90% of the most eminent scientists are self-declared Atheists. The high heritability of IQ implies that Atheists tend to have intelligent offspring. The framework predicts that their children will most likely also become Atheists,

Acknowledgements

I would like to thank Dr. C.L. Reeve and an anonymous reviewer for highly useful critique.

References (85)

  • ArgyleM. et al.

    The social psychology of religion

    (1975)
  • Beit-Hallahmi, B., (1988). The religiosity and religious affiliation of Nobel Prize winners (umpublished data cited in...
  • Beit-HallahmiB. et al.

    The psychology of religious behaviour, belief and experience

    (1997)
  • Bell, P., (2002). Would you believe it? Mensa Magazine, Feb.,...
  • BelloF.

    The young scientists

    Fortune

    (1954)
  • BrownL.B.

    A study of religious belief

    British Journal of Psychology

    (1962)
  • BurtC.

    Is intelligence distributed normally?

    British Journal of Statistical Psychology

    (1963)
  • ChristieR. et al.

    Studies in the scope and method of the “Authoritarian Personality

    (1954)
  • DearyI.J. et al.

    Bright children become enlightened adults

    Psychological Science

    (2008)
  • DawkinsR.

    The God delusion

    (2006)
  • Gallup International

    The voice of the people survey

    (2005)
  • GeertzC.

    Ideology as a cultural system

  • Harris Interactive

    While most U.S. adults believe in God, only 58 percent are ”Absolutely Certain”

    (2006)
  • Hartmann, P., Larsen, L. & Nyborg, H. (submitted for publication). Personality as predictor of...
  • HerrnsteinR.J. et al.

    The Bell curve: Intelligence and class structure in American life

    (1994)
  • HogeD.

    Commitment on campus: Changes in religion and values over five decades

    (1974)
  • HollingsworthL.

    Children above 180 IQ

    (1942)
  • HowellsT.H.

    A comparative study of those who accept as against those who reject religious authority

    University of Iowa Studies in Character

    (1928)
  • HuntR.A.

    Mythological–symbolic religious commitment: The LAM scales

    Journal for the Scientific Study of Religion

    (1972)
  • JensenA.R.

    The g factor: The science of mental ability

    (1998)
  • JensenA.R. et al.

    Physical correlates of human intelligence

  • JINFO.ORG

    Jewish Nobel Prize winners

    (2007)
  • JungR.E. et al.

    The parieto-frontal integration theory (P-FIT) of intelligence: Converging neuroimaging evidence

    Behavioral and Brain Sciences (target article)

    (2007)
  • Kanazawa, S. (in press). De gustibus est disputandum II: Why liberals and atheists are more...
  • KosminB.A. et al.

    One nation under God

    (1993)
  • KuhlenR.G. et al.

    Age differences in religious beliefs and problems during adolescence

    Journal of Genetic Psychology

    (1944)
  • LarsenL. et al.

    The stability of general intelligence from early adulthood to middle-age

    Intelligence

    (2007)
  • LarsonE.J. et al.

    Leading scientists still reject God

    Nature

    (1998)
  • LarsonE.J. et al.

    Scientists and religion in America

    Scientific American

    (1999)
  • LenskiG.E.

    The religious factor

    (1963)
  • LeubaJ.A.

    The belief in God and immortality

    (1921)
  • LordF.M.

    Application of item response theory to practical testing problems

    (1980)
  • Cited by (0)

    1

    Private address: Adslev Skovvej 2, DK-8362 Hørning, Denmark.

    View full text