Thursday, 16 February 2006

How we misunderstand evolution

Everyone thinks they understand natural selection, but very few do, Richard Dawkins surmised in his 1987 book The Blind Watchmaker. “It is almost as if the human brain were specifically designed to misunderstand Darwinism”, he wrote.

Indeed, in a new study, Andrew Shtulman found the majority of 42 Harvard undergraduates misunderstood evolution, seeing it in terms of the transformation of the essence of a species. Such students tended to believe, for example, that a parent adapts to her environment before passing her acquired characteristics onto her offspring.

Just to remind you, Darwinian evolution is a two step process based on variation within species populations: chance mutations and sexual recombinations introduce differences between individual organisms, and whether or not these are retained depends on the success or not of an individual organism’s reproduction.

Shtulman tested the students’ understanding of evolution with a comprehensive battery of questions on variation, inheritance, adaptation, domestication, speciation and extinction. For example, the students had to choose the most Darwinian explanation for why a youth basketball team did better this season than last. Students who understood evolution picked the answer “more people completed trials for the same number of team places this year”, whereas students who had an incorrect, ‘transformational’ understanding of evolution chose answers such as “each returning team member grew taller over the summer”.

As has been found with naïve students’ understanding of other scientific theories such as in thermodynamics, acoustics and cosmology, the kind of misunderstandings shown by the students here tended to parallel the development of evolutionary perspectives through history, for example mirroring aspects of theories put forward by Lamarck, Cope and Haeckel.

Could the widespread misunderstanding of evolutionary theory explain the appeal of Intelligent Design creationism? It seems not. Students who understood evolutionary theory were no more likely to believe it was the best explanation for how a species adapts to its environment than those students who misunderstood evolution.
Shtulman, A. (2006). Qualitative differences between naïve and scientific theories of evolution. Cognitive Psychology, 52, 170-194.

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

Link to paper in TICS that discusses the implications of this and related research for understanding the Intelligent Design controversy.