Flynn's Dual Component Model Of Human Intelligence

differences that manifest across the population—the domain in which neurology and genetics hold sway. And environment is potent when considering intelligence differences that manifest across time—the domain in which neurology and genetics possess no influence at all. But although this short answer does manage to resolve the paradox precisely, it does not address what is actually at issue here—namely why does Flynn think this is a paradox. There are several different analogies one might use to illustrate this essay’s dual-component model of human intelligence with its orthogonal influences of neuronal intelligence and environmental intelligence. For instance, Lewontin’s example of the batches of seed corn would do quite well. Also, one might

In other words, if an influence has no tangible impact upon the human brain, then it cannot be an influence associated with human intelligence. Thus when Flynn considers environmental forces, which he can see full well have the perfect potential for explaining the Flynn effect, he stops short when he does not see how those environmental forces can cause the supposedly requisite change in human genetics or human neurology. This would be the equivalent of Flynn stopping short because he does not see how the nitrates in the soil can impact the seed corn’s genetic structure, or stopping short because he does not see how the water level in the harbor can alter the ships’ physical characteristics. Flynn does not make this mistake when considering the seed corn or the ships in the harbor because he understands that the actions of the nitrates are orthogonal to the seed corn’s genetics, and he understands that the water level in the harbor is independent of each ship’s physical characteristics. But in the field of human intelligence, where it has become dogma that every influence must ultimately deliver its impact within the folds of the human brain, Flynn cannot countenance this kind of

For instance, two commonly touted examples of the type of environmental complexity that can lead to increased human intelligence are the widespread use of video games and the growing complexity and multivariate plot lines in television shows and movies. Others will highlight the expanded task demands that have come with increased urbanization, and some might point to the denser presence of visual symbols and graphical puzzles within everyday life. But no matter what thing or set of things is being proposed, it quickly becomes clear that these items by themselves cannot account for the ubiquitous and inexorable reach of the Flynn effect. The Flynn effect was working its magic long before there even were video games and television sets, and the Flynn effect remains prominent in locations where visual symbols and graphical puzzles have yet to take much hold, and the Flynn effect can even be noticed in rural as well as urban communities. Of course other instances of environmental and social complexity might be offered up instead, but inevitably each instance must fall victim to the shortcoming of having only limited spatial and temporal reach. The Flynn effect is a population-wide and time-persistent phenomenon, and so any explanation must