The Failure of Universalism: Test Score Differences Across Countries and Cultures
A spectre haunts human thought: If truth has many faces, then not one of them deserves trust or respect. Happily, there is a remedy: human universals. They are the Holy Water with which the spectre can be exorcized. But of course, before we can use human universals to dispel the threat of cognitive anarchy, which would otherwise engulf us, we must first find them. And so, the new hunt for the Holy Grail is on.
( Gellner, 1981, p. 1)
If mind, like brain, is one, and therefore unitary in all humans, then neuropsychological assessment founded on human universals will work equally well in London, New York, or the subsistence farming villages of South Africa and Brazil. If mind is many, however, and the ways in which people think and solve problems are determined by the interaction of their genetic endowment and the material conditions of their culture, then identical tests may make geniuses of average people in one culture and imbeciles of equally average people in another.
All psychological assessment faces these problems of culture and cognition, but they are especially acute for neuropsychology. Neuropsychologists are trained in hospital settings, in which the universality of physical diagnosis is unchallenged. The presence or absence of a pathogen in the bloodstream, nystagmus, vibration sense, or the elicitation of a reflex are all