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Philosophers and psychologists call the question of “common sense” the nativism-empiricism debate. Nativists (e.g., Plato, Descartes, Chomsky, Pinker) believe that people are born with innate perceptual abilities, and empiricists (e.g., Locke, Hume, Quine) believe that perceptual abilities are all learned abilities subject to adaptation. Philosophers argue about these questions, and psychologists conduct experiments to test these theories’ hypotheses. Their experiments have mainly centered on five types of studies: observing babies’ behavior, observing animals’ behavior, observing the behavior of adults with cataracts, observing perceptual abilities across cultures, and observing subjects’s changes in perceptual abilities longitudinally.

Some perceptions seem to be innate; others, learned. Learned abilities tend to be more complex, but not necessarily.