WHILE OUR species may be the most intelligent species on the planet at this point, our brains carry a lot of baggage from our evolutionary development that sometimes makes us irrational. This is not always a bad thing, but it requires that we be conscious of our weaknesses. We seem to be especially bad in understanding properly how the world works. Our intuitive understanding of physical processes is often wrong, and we can maintain this misunderstanding by failure to fully integrate observations that contradict it.1
In some cases, there is such resistance to science education that it never entirely sticks, and foundational biases persist into adulthood. One study tested college undergraduates’ intuitions about basic physical motions, such as the path that a ball will take when released from a curved tube (13). Many of the undergraduates retained a common-sense Aristotelian theory of object motion; they predicted that the ball would continue to move in a curved motion, choosing B over A in Fig. 1. An interesting addendum is that although education does not shake this bias, real-world experience can suffice. In another study, undergraduates were asked about the path that water would take out of a curved hose. This corresponded to an event that the participants had seen, and few believed that the water would take a curved path (14).
One of the things that we seem programmed to misunderstand is evolution. Children have a bias towards teleological explanations and nonspecific creationism (the idea that someone, if not a particular god, made an object or entity), and do not appear to have any type of intuitive evolutionary beliefs. This is in line with previous observations that children’s intuitive beliefs about physical processes tend to mimic early, obsolete scientific theories in multiple scientific disciplines.
The culture a child grows up in is influential in the formation of adult beliefs.2 Evans found that when asked about where an inanimate object, an artifact, and a living organism came from, very young children initially produce spontaneous generation explanations for all. As children age and learn about manufacturing, they explain artifacts as human-made, but tend to think that someone must have made living organisms as well (but spontaneous generation remains in favor for inanimate objects like rocks). Interestingly, 5-7 year old children raised in fundamentalist schools tend to favor creationist explanations only, while those in the general population mix spontaneous generation with creationism. Children 8-10 years old were universally creationist, while older children accepted whichever idea was the reigning paradigm in their community (but a child’s interest in natural history or in religion predicted evolutionary or creationist beliefs independently of parents’ beliefs).
Creationist explanations seem to be intuitively appealing. Creationist education hastens the transition from spontaneous generation beliefs to exclusive creationism. While a child’s interest in natural history can lead to evolutionary beliefs, it appears in general a child adopts the beliefs held by his or her community. This immediately suggests that people tend not to evaluate the theory of evolution based upon its scientific validity, but upon its acceptance by respected authority figures. This raises the question, in general, how well do people understand evolution? A recent study shows that they understand it very poorly!
Shtulman found that a sample of Harvard Summer School students (29 high school students, 13 undergrads (two from Harvard)) were split between what he called transformationalists and variationists.3 Transformationalism is a way of thinking about species that is not explicitly formulated, but instead based upon an intuitive sense that species have an inherent essence that can change over time (there is some debate about which type of essentialism he was measuring and whether past evolutionary theories were as essentialist as he thinks, so while I am more interested in his findings on students’ opinions the alternate discussion can be found here). Shtulman found that transformationalist ideas can be detected in a person’s understanding about six different aspects of evolution.
- Variation: Transformationalists think that variation in different members of a species is minor and either nonadaptive or maladaptive. Variationalists realize variation is common and can be adaptive, nonadaptive, or maladaptive, and if adaptive will contribute to heightened reproductive success.
- Inheritance: Transformationalists think that offspring will inherit traits that are most beneficial for the species regardless of whether the parents actually have these traits. Variationalists realize an adult cannot pass on a trait that it does not possess, and that traits are passed on regardless of their utility.
- Adaptation: Transformationalists realize not all organisms survive to reproduce, but think this is irrelevant to the development of a species since each organism inherits the essence of its species, and thus each should be equally fit. Variationalists recognize natural selection acting upon variation as the driving force for adaptation.
- Domestication: Here transformationalists tend to be rather Lamarckian. Domestication is not due to selection for certain alleles, but to modification of individual organisms over generations. Transformationalists tend to underestimate our ability to change a species’ phenotype. Variationalists see artificial selection as analogous to natural selection.
- Speciation: Since transformationalists think species change by modification of the species’ essence, speciation is the transformation of one species into another. Additionally, transformationalists think that structurally dissimilar species cannot be evolutionarily related. Variationalists see speciation as a branching process, and trace common ancestry to the root of life.
- Extinction: Since transformationalists see change as teleological, species should be able to manufacture the needed changes to avoid extinction. Transformationalists tend to underestimate the frequency of extinction. Variationalists know extinction is very common.
Creationists tend to understand evolution to be a transformationalist process and then (rightly, but often for the wrong reasons) reject most of these ideas. There were two probable creationists in the test sample, and both had transformationalist understandings of evolution. Anyone who has had much contact with creationists has probably run across the transformationalist depiction of speciation (i.e. “If we descended from apes, why are there still apes?”) This diagram from the paper illustrates this misunderstanding. It illustrates the ideal organization of a series of shapes according to a variationalist interpretation and a transformationalist interpretation. (WARNING: This diagram may cause physical pain to those versed in evolutionary theory!)
Another misrepresentation of evolution is the transformationalist idea that organisms manufacture phenotypic changes because they are needed. The acceptance of this idea and misapplication of it to evolution leads to the straw man that evolution requires organisms develop certain features purposefully in preparation for future challenges. In actuality, necessity sifts organisms for beneficial mutations, and in an extreme challenge the majority who don’t have what it takes die. Losers are far more common than winners in evolutionary history.
So creationists think transformationalist ideas about inheritance and speciation are accepted evolutionary theory and reject these, but tend to accept transformationalist ideas about variation, adaptation, and domestication. Creationists tend to underestimate the frequency of extinction, but that seems to be due to an unstated idea that God as Creator and Sustainer will not allow species to become extinct at too high a rate (considering the fossil record shows the vast majority of all organisms that have ever existed are extinct, this idea has little empirical support), not due to transformationalist thinking that species will elude extinction by purposeful change. However, creationists sometimes apply the transformationalist ideas about extinction to evolution and then object to evolution because they think that it requires that species avoid extinction by generating needed mutations, as mentioned above.
Nineteen of the students tested were categorized as transformationalists, yet 69% of the sample said that “natural selection is the best explanation for how a species adapts to its environment”. This means that at least some transformationalists were paying lip service to natural selection while simultaneously completely misunderstanding it. Additionally, more than half of the transformationalist students claimed to have taken a class or read a book that sufficiently explained natural selection, which Shtulman says suggests that “exposure to the concept of natural selection is necessary, but not sufficient, for learning that concept”.
I would argue that exposure to any type of information is necessary but not sufficient for learning that material, and that exposure to material in school is often not an efficient means of education. All of the transformationalist students had taken at least one biology class, yet they did not really seem to have a grasp on the basics of the theory of evolution, and could not really be said to have manufactured a coherent theoretical framework at all.
This question [if students’ naive theories of evolution should be considered “theories”] has been well debated in the aforementioned literature on evolution education. Southerland et al. (2001), for example, argue that the average student’s understanding of evolution is less like a theory and more like a heuristic, namely “need as a rationale for change.” Consistent with this claim is the finding that students of all ages prefer teleological explanations of biological change to mechanistic ones. Indeed, this finding was replicated in the present study in the sense that the transformationists used the phrases “need to,” “have to,” “in order to,” or “must” three times as often as the variationists did. Moreover, the transformationists rarely favored one, and only one, type of analogy on the analogical-reasoning questions, suggesting that they had not thought much about the mechanism responsible for species adaptation prior to participation. Indeed, the fact that evolution is simply not evident from one’s interaction with a seemingly static biological world suggests that few students would have contemplated the problem of biological adaptation prior to taking a biology class, and even fewer students would have devised their own solution to this problem.
Thus, if the term “theory” is taken to mean an explicit and highly integrated network of causal-explanatory beliefs, then it may be inappropriate to apply such a term to the average student’s understanding of evolution. If, on the other hand, this term is taken to mean any self-consistent network of causal-explanatory beliefs—explicit or implicit, dense or sparse—then the kinds of beliefs elicited in the present study should indeed be considered a theory. Without doubt, none of the participants in this study held a transformational theory of evolution as well-developed or as well-articulated as those proposed by Lamarck, Cope, or Haeckel. Nevertheless, many participants did appear to hold the same assumptions that led these biologists astray—namely, that species have essences and that these essences are transformed over time. More importantly, they did not appear to hold the same assumptions that led Darwin to infer the principle of natural selection—namely, that the individuals within a species vary and that only some of this variation is retained across generations.
It appears that transformational thinking, depending on the idea of a shared essence of a species that is amenable to modification as the need arises, is an intuitively appealing model. Moreover, it is resistant to correction by accurate evolutionary theory, and creationists tend to conflate the two models. This can prove confusing all around when a creationist tries to debate evolution by rebutting transformationalism. As Shtulman says, “If participants in the present study are at all representative of participants in the evolutionist-creationist debates waged in local courtrooms, newspapers, and school board meetings, one must wonder which theory of evolution—variationism or transformationism—is actually being debated.”
So humans have an intuitive leaning towards transformationalist thinking that is usually masked by acceptance of the views of an authority (whether evolutionist or creationist) rather than being corrected by education about evolution. Most people, whether they reject evolution or accept it, do not have much grounding in evolutionary theory at all. This generalized poor education in evolution contributes to a confusion between transformationalist thinking and evolutionary theory that provides a niche for creationism. Correction of the state of education about evolution will require a determined effort to stamp out transformationalist thinking, including education of students about transformationalism and why it is incorrect. Part of this is the removal of teleological language, which can creep into evolutionary explanation as a figure of speech but is often interpreted literally by listeners. Since intuitive misunderstandings of natural processes are difficult to correct by just explanation of theory, teaching evolution effectively will require heavy use of examples from biology and paleontology.
- Bloom, P.; Weisburg, D. S. “Childhood Origins of Adult Resistance to Science.” Science 2007, 316, 996-997. DOI:10.1126/science.1133398
- Evans, E. M. “Cognitive and Contextual Factors in the Emergence of Diverse Belief Systems: Creation versus Evolution.” Cognitive Psychology 2001, 42, 217-266. DOI:10.1006/cogp.2001.0749
- Shtulman, A. “Qualitative differences between naive and scientific theories of evolution.” Cognitive Psychology 2006, 52, 170-194. DOI:10.1016/j.cogpsych.2005.10.001