Why People Do Not Understand Evolution: An Analysis of the Cognitive Barriers to Fully Grasping the Unity of Life

Article excerpt

IN 2005, THE PARENTS OF SEVERAL STUDENTS ATTENDING Dover High School in Dover, Pennsylvania, sued the Dover Area School District over their decision to require high school biology teachers to read a statement alerting their students to the existence of "gaps" in the theory of evolution and encouraging them "to keep an open mind" regarding alternative explanations for the origins of life. The lawsuit, which the parents won, garnered national attention, as it brought to a head the controversial issue of whether Intelligent Design--the claim that complex biological systems could only have arisen through the guidance of a superior intelligence--should be taught in public schools as an alternative to evolution. In 2008, the PBS television series NOVA released a documentary on the Dover trial entitled "Judgment Day: Intelligent Design on Trial." One of the individuals interviewed for that documentary was Bill Buckingham, a member of the school board who had advocated for the inclusion of Intelligent Design in the biology curriculum. Buckingham stated that his own views on the matter were simple: "The book of Genesis tells it like it is as to how we came into being. God didn't create monkey and then take man from a monkey. He created man."

What's interesting about this quote, from a scientific perspective, is that Buckingham attributes two positions to his opponents that none actually hold, namely, (1) humans evolved from monkeys, and (2) monkeys appeared on Earth in their current form. Evolutionary biologists actually believe (1) humans and monkeys evolved from a common ancestor, and (2) monkeys evolved from earlier forms of life. In fact, biologists believe that all organisms are linked through common ancestry and that all organisms evolved from earlier forms of life. Buckingham's conceptions of the scientific ideas he attempted to censor are thus profoundly wrong, but they are not profoundly original. Similar types of misconceptions have resounded within the public sphere since 1859, when Darwin first articulated the theory of evolution by natural selection in On the Origin of Species. Today, that theory forms the backbone of the biological sciences, yet misconceptions about evolution have not declined. If anything, they have become more frequent, as the public has become more exposed to the principles and findings of evolutionary biology.


From where do such misconceptions arise? Perhaps the most popular explanation is that evolution is inconsistent with the teachings of most religions, so religious individuals simply reject the theory outright. While this idea certainly holds some truth, it fails to explain why individuals like Buckingham, who deny that evolution occurs, also tend to misunderstand what evolution is and how evolution works. Another popular explanation is that a poor understanding of evolution stems from a poor understanding of the nature of science in general, with skeptics of evolution failing to appreciate the vast extent to which it has been empirically validated. Again, while this idea holds some truth, it fails to explain why individuals who reject evolution tend not to understand the theory they are rejecting. Below, I outline an alternative explanation that has received increasing attention and support within the fields of cognitive and developmental psychology, an explanation grounded in the fact that humans tend to "essentialize" the biological world and that essentialist thinking is fundamentally incompatible with understanding the basic mechanisms of evolution.

Essentialist Thought in Everyday Life

Essentialism is the commonplace assumption that the obvious, observable properties of an object or organism are determined by some non-obvious, non-observable property at its core--its "essence." One of the best illustrations of essentialist thought is Hans Christian Andersen's tale of the ugly duckling. The tale begins with a mother duck sitting on a nest of eggs, waiting for her ducklings to hatch. …