Thursday, July 9, 2015

Is the Jury Still Out on the Scopes Trial After 90 Years?

The Scope of Evolution Includes the Psychology of Religion

Earlier this year, I visited the Rhea County Courthouse in Dayton, TN. This year marks the 90th anniversary of the Scopes “Monkey” Trial. The trial began 10 July 1925 and ended on the 21st. Science teacher John Scopes violated Tennessee law by teaching evolution. Numerous websites tell the tale.

The arguments in the 1925 trial might seem like quaint old stories unless you realize that in the U.S. a substantial minority of Christians reject scientific explanations for the origin of life in favor of a literal or near literal creationist view. In 2014, Gallup found 42% of the U. S. believes God created humans in their present form 10,000 years ago. Given the data indicating such low acceptance of biological evolution, the acceptance of an evolutionary basis for psychological functioning seems even more remote. Some readers might be aware that psychological science in general, and psychological interventions in particular, remain suspect by Christian fundamentalists without adding the additional burden of evolution.

In this post I will summarize recent thinking on evolutionary psychology.

In the next post I’ll summarize an evolutionary perspective on the psychology of religion.

An Overview of Evolutionary Psychology

As you might suspect, evolutionary psychology requires an understanding of biological evolution. Early life appeared some 3.8 billion years ago–about a half-billion years after the earth was formed. The slow process of human evolution began some 6 million years ago. Scientists have found evidence for 15 or so different species of humans. Evidence for complex behavior patterns involved in making tools and other aspects of culture appear to have evolved in the past 100,000 years. Read more at the Smithsonian website.

Human evolution occurs when adaptive genetic changes are passed from one generation to the next. Those people who survived long enough to reproduce, transmitted the genes that influenced the body and behavior of future generations. It’s obvious that humans needed food to survive and had sex to reproduce. But people may not think of the behavior patterns that also developed and are linked to routines of obtaining food, mating, fending off predators, and surviving natural disasters. The origins of many current psychological mechanisms are linked to the survival of a human species.

Natural selection is not random. Genetic variations appear to be random. Traits like eye color vary. The variations that are selected are those that support survival and reproduction.

Sexual selection is a specific selection process that drives organisms to copulate with a mate. Some acts look like examples of "Mating Gone Wild:" The peacock's tail and combat rituals are examples.

There are two common ways that sexual selection works. 1. Males compete for access to females. 2. Females choose specific mates. (Role reversals can occur in some species.)

People select plants and animals for certain characteristics. This is artificial selection.

Sex is a source of genetic variation. Genes are combined from parents during reproduction. During the process of combination, shuffling occurs. 

You can think of a psychological mechanism as a complex cognitive-emotional-behavior pattern like an app on your electronic devices.

We have software-like programs —applications—that run as needed to accomplish specific goals. Parent-child attachment, mating, social-group formation, social dominance routines, tool-making routines, and many others co-evolved with changes in anatomical structures, biological processes, and biochemical processes. As psychologist David Myers says, “everything psychological is simultaneously biological (p. 114).”

Evolutionary psychology offers psychological scientists a metatheory. Most scientists accept the principles of biological evolution. Arguments persist over details of mechanisms but not the theory. But when it comes to psychology, scientists have not yet found coherent explanations. Change is on the way.

In the last century, psychological scientists rejected the quasi-biological explanations of behavior linked to supposed instincts and drives in favor of environmental and social factors. The advent of the computer influenced thinking about the mind as a problem-solving device. Many cognitive studies focused on logical and illogical thinking, concept formation, learning and memory. Various models were proposed to account for the processing of information.

More recently, psychologists have conceded that much of our behavior is governed by automatic processes. It takes considerable effort to disengage these routines (I like the metaphor of apps.) in favor of effortful and time-consuming thought. Where do these behavioral routines come from? As you might suspect, evolutionary psychologists think these natural ways of behaving have their origins in our evolutionary past.

Kirkpatrick’s View on Evolutionary Psychology

In his update on “Evolutionary Psychology as a Foundation for the Psychology of Evolution,” Lee Kirkpatrick suggests three ways evolutionary psychology influences psychology.

1. Psychological processes evolved to support selection processes. The widely documented attachment process is an example of a psychological process that enhances the odds of survival for infants to reproductive age. Thus, psychological processes subserve natural selection. Similarly, human mating routines subserve sexual selection in the quest for the fittest mates.

2. Much of human behavior can be linked to by-products of adaptations. Adaptations like language can easily be linked to survival. But complex ways of communicating in writing and art would be by-products in this view. Another kind of by-product is an exaptation.

Exaptations make use of biological adaptations. Adding lenses to enhance vision and perching them on noses are examples of exaptations. Understanding human nature requires an understanding of which adaptation is the result of an evolutionary process and which is a by-product of a more basic process.

Scientists Stephen Jay Gould and Richard Lewontin are credited with identifying byproducts of evolution that had little survival value. These are called spandrels or exaptations.

3. Adaptations evolve slowly over long periods of time. Any psychological adaptations evolved in response to environments faced by distant ancestors. Our desire for sweet and fatty foods leads to obesity in modern environments where such products are easily obtained with minimal effort compared to the high calorie expended in ancient times.


Kirkpatrick, L.A. (2013). Evolutionary psychology as a foundation for the psychology of evolution. In R. F. Paloutzian and C.L. Park (eds.) 118-137. Handbook of the psychology of religion and spirituality, 2nd ed. New York: Guilford.

Myers, D. (2012) Psychology in Everyday Life, 2nd ed. New York: Worth.

Additional resources

A related post: Did the Pope Evolve

Sutton, G. W. (in press). [Review of the book Handbook of The psychology of religion and spirituality (Second Edition) by Raymond F. Paloutzian and Crystal L. Park (Editors). Encounter (Accepted)

Sutton, G. W. (2008). [Review of the book Why Darwin matters: The case against intelligent design by
 M. Shermer]. Journal of Psychology and Christianity, 27, 181.  Academia Link

Web sites

Creationist viewpoint can be found at

Darwin online

Intelligent Design viewpoint can be found at

Why Evolution is True by Jerry Coyne

Ted Talks videos on evolution

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