Thursday, January 05, 2012

What IQ Tests Test

This paper (PDF) by Ken Richardson is worth a read.

My favorite passage:

The IQ test is predicated on a simple biometric model of intelligence. Although essentially uncharacterized, the model assumes a domain-general computational function with population variance arising in simple parameters like ‘capacity’, ‘speed’ and ‘efficiency’ (Jensen, 1998). Likewise, problem-solving ability across individuals varies with those parameters irrespective of the problems’ history and current context. 

However, alternative theorists, from Binet (see Zenderland, 1998) to contemporary developmentalists, have maintained the need for more ‘psychological’ models of cognition. These include recent ‘ecological’ (e.g. Wozniak & Fischer, 1993) and sociohistorical perspectives (e.g. Cole, Engestro ̈m, & Vasquez 1997; Richardson, 1998; Wertsch, del Río & Álvarez, 1995). In these perspectives, advanced cognitive systems evolved for coping with highly changeable, unpredictable circumstances, especially those that arise—or, indeed, are created—in social contexts (Donald, 1991). These are not dealt with by stereotyped computational mechanisms but by distilling the abstract informational structure (i.e. knowledge) peculiar to each problem domain. Such representations can then be used as ‘psychological tools’ to generate processes unique to the problem, but informed by that knowledge structure. Intelligent performances are thus based on an interaction between the ‘structure’ of the current problem and developed representations (i.e. knowledge), rather than stereotyped ‘reasoning processes’ that merely vary in speed or efficiency. 

An important aspect of this perspective is that the complexity of structure of problems is vastly amplified in humans by being embedded in socially cooperative activities (Donald, 1991). In general, these are organized and regulated by socially evolved ‘cultural tools’. Cultural tools include historically evolved patterns of co-action; the informal and institutionalized rules and procedures governing them; the shared conceptual representations underlying them; styles of speech and other forms of communication; administrative, management and accounting tools; specific hardware and technological tools; as well as ideologies, belief systems, social values, and so on (Vygotsky, 1988).

In sum, cultural tools prevail as the very means of human existence in any society. In sociohistorical theory, the forms of these cultural tools become internalized in individuals as the dominant ‘psychological tools’ (Vygotsky, 1988). Culture is thus more than mere clothing on human cognition, and forms of intelligence are more than something merely ‘valued’ by a culture, as both Gardner (1983) and Sternberg (e.g. 1999) suggest. Rather, culture is constitutive of its form and function—the ‘technologies of the intellect’, as Olson (1986) calls them. As Cole put it, ‘The structure of thought depends upon the structure of the dominant types of activity in different cultures’ (quoted by Luria, 1976, pp. xiv–xv). In addition, culture incorporates an already self-variegating, adaptable, cognitive system into a further system of variegation. In consequence, sociocognitive variation is both fundamentally different from, and vastly greater than, variation in a simple quantitative trait (and for very good evolutionary reasons). Generally speaking, this means that intelligence differentiates both ‘horizontally’ and ‘vertically’: horizontally, in variegating qualitatively, like languages or the products of the immune system; vertically, in the sense of degree of developed acquisition of specific cultural tools. 

The IQ test collapses this rich and complex variegation in human cognition into a single scale as follows. In societies organized through hierarchical divisions of labour, different social classes will (by definition) utilize the different ‘cultural tools’ of society to different extents. Parents will thus vary in the degree to which they are cognitively enfranchised in the use of different cultural tools, so that their children will be prepared for acquiring them to varying degrees (and with different degrees of importance and emphasis—see below). Yet IQ tests, the items of which are designed by members of a rather narrow social class, will tend to test for the acquisition of a rather particular set of cultural tools: in effect, to test, or screen, for individuals’ psychological proximity to that set per se, regardless of intellectual complexity or superiority as such. 

I must say that this comes a close second:

"The assertion that IQ measures human intelligence in any general sense, or that the source of variance in IQ scores is primarily cognitive in nature, remains unsubstantiated after decades of investigation. The hypothetical ‘general ability’, or g, remains as inscrutable as the ‘vital forces’ once thought to distinguish living from non-living things."