Cognitive biases and science


It may be obvious that people tend to trust their intuition over data, but some counterintuitive facts or forces are questioned (i.e. evolution), while other are not (i.e. electricity, the non-flatness of the earth). This review (entitled Childhood Origins of Adult Resistance to Science– I can’t tell if the title is deliberately clever or entirely serious) takes a look at why, concluding (perhaps unsurprisingly) that resistance to scientific information is exacerbated in societies “where nonscientific ideologies have the advantages of being both grounded in common sense and transmitted by trustworthy sources.” I tried to pick out some select quotes, but instead I’m just putting the whole thing below the fold. It’s a fascinating article, and very well-written:

Scientists, educators, and policy-makers have long been concerned about American adults’ resistance to certain scientific ideas (1). In a 2005 Pew Trust poll, 42% of respondents said that they believed that humans and other animals have existed in their present form since the beginning of time, a view that denies the very existence of evolution (2). Even among the minority who claim to accept natural selection, most misunderstand it, seeing evolution as a mysterious process causing animals to have offspring that are better adapted to their environments (3). This is not the only domain where people reject science: Many believe in the efficacy of unproven medical interventions; the mystical nature of out-of-body experiences; the existence of supernatural entities such as ghosts and fairies; and the legitimacy of astrology, ESP, and divination (4). This resistance to science has important social implications, because a scientifically ignorant public is unprepared to evaluate policies about global warming, vaccination, genetically modified organisms, stem cell research, and cloning (1).


The main source of resistance concerns what children know before their exposure to science. Recent psychological research makes it clear that babies are not “blank slates”; even 1-year-olds possess a rich understanding of both the physical world (a “naÃ¯ve physics”) and the social world (a “naÃ¯ve psychology”) (5). Babies know that objects are solid, persist over time (even when out of sight), fall to the ground if unsupported, and do not move unless acted upon (6). They also understand that people move autonomously in response to social and physical events, act and react in accord with their goals, and respond with appropriate emotions to different situations (5, 7, 8).


Children’s belief that unsupported objects fall downward, for instance, makes it difficult for them to see the world as a sphereâ€”if it were a sphere, the people and things on the other side should fall off. It is not until about 8 or 9 years of age that children demonstrate a coherent understanding of a spherical Earth (10), and younger children often distort the scientific understanding in systematic ways. Some deny that people can live all over Earth’s surface (10), and when asked to draw Earth (11) or model it with clay (12), some children depict it as a sphere with a flattened top or as a hollow sphere that people live inside.

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).




The main reason why people resist certain scientific findings, then, is that many of these findings are unnatural and unintuitive. But this does not explain cultural differences in resistance to science. There are substantial differences, for example, in how quickly children from different countries come to learn that Earth is a sphere (10). There is also variation across countries in the extent of adult resistance to science, including the finding that Americans are more resistant to evolutionary theory than are citizens of most other countries (24).

Part of the explanation for such cultural differences lies in how children and adults process different types of information. Some culture-specific information is not associated with any particular source; it is “common knowledge.” As such, learning of this type of information generally bypasses critical analysis. A prototypical example is that of word meanings. Everyone uses the word “dog” to refer to dogs, so children easily learn that this is what they are called (25). Other examples include belief in germs and electricity. Their existence is generally assumed in day-to-day conversation and is not marked as uncertain; nobody says that they “believe in electricity.” Hence, even children and adults with little scientific background believe that these invisible entities really exist (26).

Other information, however, is explicitly asserted, not tacitly assumed. Such asserted information is associated with certain sources. A child might note that science teachers make surprising claims about the origin of human beings, for instance, whereas their parents do not. Furthermore, the tentative status of this information is sometimes explicitly marked; people will assert that they “believe in evolution.”


Science is not special here; the same process of deference holds for certain religious, moral, and political beliefs as well. In an illustrative recent study, participants were asked their opinion about a social welfare policy that was described as being endorsed by either Democrats or Republicans. Although the participants sincerely believed that their responses were based on the objective merits of the policy, the major determinant of what they thought of the policy was, in fact, whether or not their favored political party was said to endorse it (27). Additionally, many of the specific moral intuitions held by members of a society appear to be the consequence, not of personal moral contemplation, but of deference to the views of the community (28).

Adults thus rely on the trustworthiness of the source when deciding which asserted claims to believe. Do children do the same? Recent studies suggest that they do; children, like adults, have at least some capacity to assess the trustworthiness of their information sources. Four- and five-year-olds, for instance, know that adults know things that other children do not (like the meaning of the word “hypochondriac”) (29), and when given conflicting information from a child and from an adult, they prefer to learn from the adult (30). They know that adults have different areas of expertise: Doctors know how to fix broken arms, and mechanics know how to fix flat tires (31, 32). They prefer to learn from a knowledgeable speaker than from an ignorant one (29, 33), and they prefer a confident source to a tentative one (34). Finally, when 5-year-olds hear about a competition whose outcome was unclear, they are more likely to believe a person who claimed that he had lost the race (a statement that goes against his self-interest) than a person who claimed that he had won the race (a statement that goes with his self-interest). In a limited sense, then, they are capable of cynicism (35).


References and Notes

* 1. H. Nowotny, Science 308, 1117 (2005).[Abstract/Free Full Text]
* 2. “Teaching of Creationism is Endorsed in New Survey” New York Times, 31 August 2005, p. A9.
* 3. A. Shtulman, Cognit. Psychol. 52, 170 (2006). [CrossRef] [ISI] [Medline]
* 4. M. Shermer, Why People Believe Weird Things: Pseudoscience, Superstition, and Other Confusions of Our Time (Owl Books, New York, 2002).
* 5. P. Bloom, Descartes’ Baby (Basic Books, New York, 2004).
* 6. E. Spelke, Cognition 50, 431 (1994). [CrossRef] [ISI] [Medline]
* 7. G. Gergely, Z. Nadasdy, G. Csibra, S. Biro, Cognition 56, 165 (1995). [CrossRef] [ISI] [Medline]
* 8. V. Kuhlmeier, K. Wynn, P. Bloom, Psychol. Sci. 14, 402 (2003). [CrossRef] [ISI] [Medline]
* 9. S. Carey, J. Appl. Dev. Psychol. 21, 13 (2000). [CrossRef] [ISI]
* 10. M. Siegal, G. Butterworth, P. A. Newcombe, Dev. Sci. 7, 308 (2004). [CrossRef] [ISI] [Medline]
* 11. S. Vosniadou, W. F. Brewer, Cognit. Psychol. 24, 535 (1992). [CrossRef] [ISI]
* 12. S. Vosniadou, in Mapping the Mind, L. Hirschfeld, S. Gelman, Eds. (Cambridge Univ. Press, New York, 2003), pp. 412â€“430.
* 13. M. McCloskey, A. Caramazza, B. Green, Science 210, 1139 (1980).[Abstract/Free Full Text]
* 14. M. K. Kaiser, J. Jonides, J. Alexander, Mem. Cogn. 14, 308 (1986). [ISI] [Medline]
* 15. D. Kelemen, Cognition 70, 241 (1999). [CrossRef] [ISI] [Medline]
* 16. M. Evans, Cognit. Psychol. 42, 217 (2001). [CrossRef] [ISI] [Medline]
* 17. A. S. Lillard, Child Dev. 67, 1717 (1996). [CrossRef] [ISI] [Medline]
* 18. C. N. Johnson, Child Dev. 61, 962 (1990). [CrossRef] [ISI] [Medline]
* 19. F. Crick, The Astonishing Hypothesis (Simon & Schuster, New York, 1995).
* 20. This belief in souls also holds for some expert ethicists. For instance, in their 2003 report Being Human: Readings from the President’s Council on Bioethics, the President’s Council described people as follows: “We have both corporeal and noncorporeal aspects. We are embodied spirits and inspirited bodies (or, if you will, embodied minds and minded bodies)” (21).
* 21. The President’s Council on Bioethics, Being Human: Readings from the President’s Council on Bioethics (The President’s Council on Bioethics, Washington, DC, 2003).
* 22. J. D. Greene, J. D. Cohen, Philos. Trans. R. Soc. London Ser. B 359, 1775 (2004). [CrossRef] [ISI] [Medline]
* 23. M. Gazzaniga, The Ethical Brain (Dana, Chicago, 2005).
* 24. J. D. Miller, E. C. Scott, S. Okamoto, Science 313, 765 (2006).[Abstract/Free Full Text]
* 25. P. Bloom, How Children Learn the Meanings of Words (MIT Press, Cambridge, MA, 2000).
* 26. P. L. Harris, E. S. Pasquini, S. Duke, J. J. Asscher, F. Pons, Dev. Sci. 9, 76 (2006). [CrossRef] [ISI] [Medline]
* 27. G. L. Cohen, J. Pers. Soc. Psychol. 85, 808 (2003). [CrossRef] [ISI] [Medline]
* 28. J. Haidt, Psychol. Rev. 108, 814 (2001). [CrossRef] [ISI] [Medline]
* 29. M. Taylor, B. S. Cartwright, T. Bowden, Child Dev. 62, 1334 (1991). [CrossRef] [ISI] [Medline]
* 30. V. K. Jaswal, L. A. Neely, Psychol. Sci. 17, 757 (2006). [CrossRef] [ISI] [Medline]
* 31. D. J. Lutz, F. C. Keil, Child Dev. 73, 1073 (2002). [CrossRef] [ISI] [Medline]
* 32. J. H. Danovitch, F. C. Keil, Child Dev. 75, 918 (2004). [CrossRef] [ISI] [Medline]
* 33. M. A. Koenig, F. Clement, P. L. Harris, Psychol. Sci. 15, 694 (2004). [CrossRef] [ISI] [Medline]
* 34. M. A. Sabbagh, D. A. Baldwin, Child Dev. 72, 1054 (2001). [CrossRef] [ISI] [Medline]
* 35. C. M. Mills, F. C. Keil, Psychol. Sci. 16, 385 (2005). [CrossRef] [ISI] [Medline]
* 36. We thank P. Harris and F. Keil for helpful comments on an earlier version of this manuscript. Neither author received any funding for the preparation of this article.



  1. I heard the authors interviewed in a sciece podcast and they were reasonable, despite my expectations. 
    Basically they said scientists need to stay out of politics to gain more trust, something that many other counsel against.

  2. Sometimes intuitions about the natural world can hinder the learning of scientific theories, but the best case is when scientific models can be constructed so as to make use of those intuitions that are already there. Thus, for example, the idea of an “energy landscape” for a chemical reaction allows some of the common-sense notions of how objects move over a physical, material surface to be applied to the trajectory of molecules through the transition state.

  3. I’m not sure the quote from the Bioethics Commission in ftn. 20 is really dualism. It sounds more like neutral monism to me.

    I must say that I somehow support this opinion in the following sense: 
    Though brain and mind are the same “thing” the brain in is an “outside view” and the mind is an “inside view” and neither is the “real thing” but only a peculiar and necessarily incomplete VIEW of the real thing. 
    I don’t like to call this dualism since I am pretty sure that there is an unique underlying “reality” behind both views.