“The Science of Cycology: Failures to Understand How Everyday Objects Work”, 2006-12-01 (; similar):
[drawings] When their understanding of the basics of bicycle design was assessed objectively, people were found to make frequent and serious mistakes, such as believing that the chain went around the front wheel as well as the back wheel. Errors were reduced but not eliminated for bicycle experts, for men more than women, and for people who were shown a real bicycle as they were tested.
The results demonstrate that most people’s conceptual understanding of this familiar, everyday object is sketchy and shallow, even for information that is frequently encountered and easily perceived.
This evidence of a minimal and even inaccurate causal understanding is inconsistent with that of strong versions of explanation-based (or theory-based) theories of categorization.
I think I know less than I thought.
Participant’s comment, after completion of the bicycle drawing task
Recent research has suggested that people often overestimate their ability to explain how things function. 2002 found that people overrated their understanding of complicated phenomena. This illusion of explanatory depth was not merely due to general overconfidence; it was specific to the understanding of causally complex systems, such as artifacts (crossbows, sewing machines, microchips) and natural phenomena (tides, rainbows), relative to other knowledge domains, such as facts (names of capital cities), procedures (baking cakes), or narratives (movie plots). 2002; (see also 2004) investigated why people overestimated their knowledge and which factors changed their ratings when they were confronted with evidence of the inadequacy of their understanding. 2002 found that people reduced their estimation of their own knowledge after having to provide functional explanations. Similarly, studies of naive physics have demonstrated that adults’ understanding of mechanics (eg. trajectories of falling objects and displacement of liquids; et al 1992 [cf. Newtonian & quantum mechanics]) and optics (eg. mirrors; et al 2003 [see also “extramission theory”]) is often sketchy, inaccurate, and inconsistently applied.
The present findings are more surprising, for they suggest that we may not acquire an understanding of how an object such as a bicycle works even if the necessary information is readily available in our everyday environment (see note 1). We may only rarely try to provide explanations or to test the consistency of our fragmented understanding of the world (2001).
…Keil and Wilson (2003b; 2000), however, have argued that the finding that people have an illusion of explanatory depth (2002) is not necessarily inconsistent with explanation-based theories, even though such theories assume that causal and functional knowledge underpin our concepts. 2003b has suggested that, even if our understanding of how objects function is fragmentary and shallow, it may be sufficient to track the causal structure of the world. Furthermore, this minimal understanding would benefit us by not overburdening our limited information-processing and information-storage capacities.