My motivation for posting this blog is simple: I am wondering whether it is possible for humans to ever truly internalize counterintuitive scientific principles like evolutionary theory or Newtonian (let alone Einsteinian) physics.

According to developmental psychologists like Elizabeth Spelke or Susan Carey, and cognitive anthropologists like Pascal Boyer and Dan Sperber, humans are endowed with inference mechanisms that enable them to acquire knowledge of the world (these inference mechanisms are known by several terms, such as core knowledge, conceptual modules or intuitive ontologies). Sometimes these inference mechanisms are at odds with scientific principles. A well-studied example is impetus physics, the view that inanimate objects, in order to be propelled, have to be laden with a force (impetus) by an agent or another object in order to be set in motion. This impetus physics yields a lot of imprecise predictions: for example, over 50% of adults believe that a ball, being launched by a sling, will continue in a curvilinear path, or that a ball dropped by a running person will fall straight down instead of describing a parabolic path. Newtonian physics, in contrast, predicts a parabolic path, a prediction only consistently made by people with a college training in physics (see McCloskey's 1983 review in Scientific American to get an idea).

However, an ingenious experimental procedure by Kohhenikov and Hegarty (2001), Psychonomic Bulletin & Review, 8) shows that even expert physicists are guided by the intuitive impetus physics under some conditions.

In their study, expert physicists had to remember the location of objects 'frozen' after moving along a trajectory. Afterwards, the objects vanished, and they had to recall their position. Typically, they remembered the object somewhat further along its trajectory, along a path best described by impetus physics, not Newtonian physics. So the question this raises for me is: are we ever able to truly internalize scientific and other forms of formal knowledge, or are we somehow always guided by our intuitive beliefs?

Another study that is now available through online first in Cognition also pertains to this puzzle. This study by Kelemen and Rosset (in press) examines the tendency of adults to provide teleological (i.e., goal-directed) explanations. It builds upon earlier work by Kelemen and others which showed that preteenage children have a preference for teleological explanations, they are 'promiscuous teleologists'., meaning that they see the function of a specific object as a necessary and sufficient explanation for that object. For example, when offered the choice to explain why rocks are pointy, they consistently choose teleological accounts (e.g., so that animals can scratch on them when they get itchy) over mechanistic explanations (e.g., bits of rubbish piled up over time). Not only do children prefer such explanations, they also offer them as accounts for why entire organisme exist (e.g., lions are to go in the zoo) or natural kinds (e.g. clouds are for raining). Adults typically don't endorse teleological accounts once they have acquired non-teleological causal mechanistic explanations. Although mountains can be climbed, few people would endorse the claim that mountains are there to climb on.

However, Tania Lombrozo and colleagues (2007, Psychological Science 18) recently found that Alzheimer patients have a re-emerging preference for teleological explanations: they are more prone to believe that water is there, for example, so that animals and plants can drink. So perhaps our promiscuous teleology is not fundamentally replaced by causal mechanistic explanations, but only masked by our explicitly acquired knowledge. This idea is strengthened by the study by Kelemen and Rosset's study, where adults were presented with teleological and non-teleological explanations. When they had to judge these explanations at a glance (speeded judgments), they were again more prone to endorse teleological accounts such as ‘the sun radiates heat because warmth nurtures life’.