James Flynn, in his book What is Intelligence (Flynn 2007), lists several paradoxes he associates with intelligence and the Flynn effect. One of his paradoxes (labeled as the identical twins paradox) is described by Flynn as follows:
“There is no doubt that twins separated at birth, and raised apart, have very similar IQs, presumably because of their identical genes. Indeed a wide range of studies show that genes dominate individual differences in IQ and that environment is feeble. And yet, IQ gains are so great as to signal the existence of environmental factors of enormous potency. How can environment be both so feeble and so potent?”
In a previous post, Flynn Effect 101, I provide a description of human intelligence that portrays it as consisting of two separate aspects. The first aspect is labeled as environmental intelligence, and is defined to be the amount of non-biological pattern, structure and form tangibly contained within a given physical environment. The second aspect is labeled as individual intelligence, comparable to what gets measured on intelligence tests and defined as an individual's ability to absorb environmental intelligence and respond constructively to it.
One of the merits of this description is that it resolves Flynn's identical twins paradox, by showing that it is not paradoxical at all.
Here is a short summary of the hypothetical example created in Flynn Effect 101 to demonstrate the concepts of environmental intelligence and individual intelligence:
At time 1, the environment contains a certain amount of non-biological pattern, structure and form (environmental intelligence) measured as 200 ei. [Both the number and unit are arbitrary. For the example, all that's required is that the quantified amount be less than it will be at time 2.] Also at time 1, there are three individuals named A1, B1, and C1, who based upon their population-normed performances on intelligence tests display the following set of intelligence results:
Time 1 Environmental Intelligence: 200 ei.
Time 1 Test Performance:
- A1: 80% of environmental intelligence mastered (high intelligence)
- B1: 70% of environmental intelligence mastered (medium intelligence)
- C1: 60% of environmental intelligence mastered (low intelligence)
Time 1 Absolute (Raw) Intelligence Score:
- A1: 160 ei (80% times 200 ei)
- B1: 140 ei (70% times 200 ei)
- C1: 120 ei (60% times 200 ei)
At time 2—assumed to be several generations later—the amount of non-biological pattern, structure and form located in the human environment has increased to the point where it can now be measured at 400 ei. A2, B2 and C2, identified as biologically equivalent descendents of A1, B1, and C1, perform as follows on the time 2 intelligence tests:
Time 2 Environmental Intelligence: 400 ei.
Time 2 Test Performance:
- A2: 80% of environmental intelligence mastered (high intelligence)
- B2: 70% of environmental intelligence mastered (medium intelligence)
- C2: 60% of environmental intelligence mastered (low intelligence)
Time 2 Absolute (Raw) Intelligence Score:
- A2: 320 ei (80% times 400 ei)
- B2: 280 ei (70% times 400 ei)
- C2: 240 ei (60% times 400 ei)
At any given point in time—whether it be time 1, time 2, or any other we might consider—it is individual intelligence, in the form of relative intelligence scores, that dominates the psychometric landscape. Using point-in-time scores alone, cognitive scientists can gather a wealth of information about relative human intelligence, including such statistics as g factor analysis and correlations to academic and career achievement. And as Flynn has rightly noted, in the real world these statistics lead to the inevitable conclusion that individual intelligence differences are produced primarily by genetically-driven biological forces. At any given point in time, environment scarcely gets to play a role at all; it is, as Flynn suggests, utterly feeble.
Furthermore, individual intelligence differences, as seen in both the hypothetical example and in real-world numbers, remain extremely constant over time, precisely as we might expect for a phenomenon being produced from a biological source. The human biological form—genetics, neurons, and all—does not rapidly transform over a stretch of time. And indeed, we have every reason to expect that the human biological factors determining individual intelligence would have been working in much the same way as they do now from as early as tens of thousands of years ago. When it comes to individual intelligence, biology is more than just potent—it is constant and dominant.
And yet … over time, while human biology has remained constant, the absolute level of human intelligence has relentlessly and ubiquitously continued to grow.
Cognitive scientists immediately go off track by trying to attribute this phenomenon known as the Flynn effect to those same biological components underlying individual intelligence, when in fact there is no logically compelling reason to do so. It is only a prejudice that convinces scientists to believe that the material form of human intelligence must be generated inside the human brain. In the hypothetical example above, it is clearly not a biological force that is generating the across-time raw intelligence advances. The increase in absolute levels of intelligence from time 1 to time 2 are driven solely by the increase in environmental intelligence, by the increase in non-biological pattern, structure and form tangibly contained within the physical environment.
The phenomenon of environmental intelligence is not widely recognized, but one can hardly say this is because the phenomenon is unobservable. Just a cursory glance at human history from the time of man's great leap forward, as well as a cursory glance at the rapidly transforming human landscape, should be more than adequate to convince even the greatest skeptic that there has been an ever-increasing amount of non-biological pattern, structure and form being continuously introduced into the human environment. Neural biology is constant—the constant ability to absorb pattern, structure and form—but that constant ability encounters an ever-expanding target. Over time, it is the environment—the entire environment—that becomes the dominant factor driving massive, population-wide intelligence gains. Biology, including genetics, scarcely gets to play a role at all; it is, in this domain, utterly feeble.
There is a simple analogy for the relationship between individual intelligence and environmental intelligence. Think of some ships in a harbor, including lightweight ships such as pleasure craft and heavy duty ships such as battle cruisers. We can take a measurement (relative to a fixed vertical point on land) of the bottommost part of each ship and we'll discover that there are some significant differences. Some ships will sit higher, some will sit lower. Through further analysis of such characteristics as geometric structure and material density (equivalent to psychometric analysis), we can identify ship-based factors that determine relative vertical positions in the water, exactly as we presently determine factors such as genetics that seem to drive intelligence differences among individuals.
If we then move forwards in time, we might discover that a comprehensive measurement reveals all the same relative differences in bottommost positions of the ships (with the same factors driving these relative differences), and yet we also discover that the absolute position of each ship has risen by a significantly large amount. If we make the mistake of trying to explain this increase by appealing to the characteristics of the ships themselves, we will get nowhere; the characteristics of the ships can help explain their relative vertical positions, but they do nothing for explaining their change in absolute vertical position. For that, we must turn to the context (the environment) of these ships, and in this case it is of course the water that is serving (literally) as the rising tide that raises all ships.
Environmental intelligence, the amount of non-biological pattern, structure and form tangibly contained within the physical environment, serves as the universal context of human intelligence—the relentless, ubiquitous increase in environmental intelligence has been the dominant factor driving the Flynn effect. Individual intelligence, defined as the ability to absorb environmental intelligence and respond constructively to it, remains stable in the human population over time, as is to be expected from a genetically-determined, biologically-driven skill. Both components are potent, each in its own domain; and viewed in this light, Flynn's identical twins paradox swiftly disappears.
(Flynn 2007): Flynn, James R. 2007. What Is Intelligence?: Beyond the Flynn Effect. Cambridge: Cambridge University Press.