Why are rocks pointy?

    The universe is a complex place that is difficult to understand. Our comprehension of it has improved over time, especially since the scientific revolution of the 16th and 17th centuries. Of course, humans are not born with an innate understanding of most scientific principles, but have to learn them as adolescents and adults. This is evident when we hear the humorous ways in which young children explain the natural world.

    Psychologist Deborah Kelemen at Pennsylvania State University conducted an experiment to test how children?s understanding of the world differed from adults. The experiment consisted of asking the participants to explain why biological and inanimate things possessed the characteristics they did.

    The participants were introduced to an aquatic dinosaur, and they were asked to explain why the dinosaur had a long neck. They were presented with an explanation that did not indicate a purpose such as ?The dinosaur had a long neck because the stuff inside got all stretched out and curved.? They were also given an explanation that was self-serving, such as the dinosaur has the long neck ?so that it could grab at fish? as well as a social explanation, such as ?so that it could hold up friends who are tired of swimming.?

    Here, adults preferred teleological (purpose-driven) explanations over physical explanations. Additionally, they preferred self-serving explanations over social explanations for biological properties. Children also preferred teleological explanations for biological properties, but showed a greater willingness than adults to choose social explanations. 

    The subjects were also asked to explain the characteristics of non-living objects. One of their questions was ?Why are rocks pointy?? The subjects could answer with a natural explanation that indicated the pointy-ness had no purpose at all by choosing ?rocks are pointy because stuff builds up on them over time.? They heard other possible answers that were purpose-oriented, such as ?rocks are pointy so animals do not sit on them and smash them,? and ?rocks are pointy so animals can scratch on them when they get itchy.?

    Adults overwhelmingly selected the natural, purpose-less explanation for the rocks? jagged edges. Children, on the other hand, thought of purpose-driven explanations for everything. Interestingly, the kinds of teleological explanations children offered depended on their age. First-graders were more likely than older children to believe rocks were pointy for their own sake, so that animals wouldn?t smash them.

    Second-graders were less discriminating and preferred any kind of functional account over a natural account of, say, why sand was grainy. They were just as likely to choose the self-serving explanation, ?sand is grainy so that it will not blow away? as they were to choose the socially oriented one, ?sand is grainy so that animals can easily bury their eggs in it.? Fourth-graders preferred social explanations for non-living objects, believing the sharp edges of rocks and the granularity of sand exist for the benefit of living organisms.

    I think the best explanation for why children see purpose behind even lifeless rocks and sand is that they?ve found that is a good way to understand the world. Children don?t know anything about electricity, but they realize that lightbulbs exist so that we can see in dark rooms. They grow up around thousands of artifacts which really are designed for a purpose, and extrapolate from their experience that that must be true of everything.

    Of course, it seems silly to think of rocks? edges as a self-defense mechanism, but children are not accustomed to thinking of the natural processes that produce the contents of the physical world. Kelemen notes that prior to Isaac Newton, Charles Darwin and the popularization of mechanistic theories of the world, adults were not accustomed to thinking this way either, and saw purpose behind the rain and the sun that allowed them to flourish.