Currently, Prof Linda Gottfredson, University of Delaware
is giving her Lifetime Achievement award talk “Empirical Treasure, Lost and Found”
In 1904 Charles Spearman demonstrated that human intelligence is a general
capacity, that is, it aids performance in diverse activities and content domains. His
discovery lay fallow until Arthur Jensen realized how profound it was. This single fact
about intelligence, its generality, allowed him to predict that g’s genetic roots would be dispersed in the genome and its physiological manifestations distributed across the
brain. He showed at the behavioral level that individual and group differences in g
generate predictable variations in performance whenever tasks require us to mentally
manipulate information—learn, reason, think abstractly, “connect the dots,” “figure
things out,” and so on. Jensen gradually built a theoretically coherent body of empirical evidence, a nomological network, integrating many types of evidence and attracting other scholars to the enterprise.
Jensen reintroduced Spearman’s discovery about the time I entered graduate
school (1973). It was the worst of times for objective inquiry into a trait so enmeshed in socioeconomic outcomes. Social scientists were disparaging the notion of intelligence and tests that measure it. Leading figures in my discipline, sociology, asserted that differences in ability and achievement are manufactured by elites to maintain their privileges. Some said that most everyone could do almost any job, and one that doctors could work their way up from orderly.
Their assertions violated common sense, ignored evidence in other disciplines,
and assumed causal forces never demonstrated empirically. I therefore began looking
more deeply into mechanisms that might generate occupational inequality — not just
differences in the occupations individuals prefer and enter, but also how today’s finely
graded occupational prestige hierarchy evolved in the first place. That search soon led to g and, more importantly, to asking exactly which aspects of a job magnify the
advantages of higher g. The answer, found in job analyses data, was anything that
increases the complexity of a job’s information processing demands: irrelevant, abstract, additional, or insufficient information; ambiguity, novelty, and uncertainty; need to continually update knowledge, draw inferences, spot lurking hazards, visualize the unobservable, and much more. Complexity is also the active ingredient in IQ tests and what modern life heaps upon us. We all have to contend with its proliferating cognitive burdens, but they weigh more heavily on individuals lower on the IQ continuum or experiencing normal age-related cognitive decline.
Following g’s footprints across the social landscape led me from one discipline
to another, each stopover replicating my experience as a Peace Corps volunteer in South East Asia—being the proverbial Man from Mars. It always yielded unexpected
insights. One was the transformative power of individually inconsequential effects that cumulate over time, tasks, or populations. Another was that we can improve the welfare of less able citizens—literally, reduce their disproportionately high odds of premature death—without having to raise their intelligence. That is what occupies me now— bringing critical tasks in health self-care within the cognitive reach of patients currently unable to perform them effectively (i.e., “non-compliant” patients).