Given that limitation, my current median expectation, based primarily on summaries of a reanalysis of the Terman Study, is that above about 135 for men (and 125 for women), high IQ tends to contingently lead to social dysfunction due to loneliness and greater potential for the development of misanthropy. Basically it seems to produce difficulties "playing well with others" rather than superior performance from within an integrated social network, simply because there are so many less intelligent people functioning as an isolating buffer, incapable of understanding things that seem obvious to the high IQ person. This is a contingent problem in the sense that if dumb people were all "upgraded" to equivalent levels of functioning then a lot of the problem would go away and you might then see people with an IQ of 160 not having these problems.
Which re-analysis was that? The material I am aware of show that income continues to increase with IQ as high as the scale goes, which certainly doesn't sound like dysfunction; eg "'The Effects of Education, Personality, and IQ on Earnings of High-Ability Men', Gensowski et al 2011" (similar to SMPY results). And from "Rethinking Giftedness and Gifted Education: A Proposed Direction Forward Based on Psychological Science", which is very germane to this discussion:
Some subscribe to the ability-threshold/creativity hypothesis, which postulates that the likelihood of producing something creative increases with intelligence up to about an IQ of 120, beyond which further increments in IQ do not significantly augment one’s chances for creative accomplishment (Dai, 2010; Lubart, 2003). There are several research findings that refute the ability-threshold/creativity hypothesis. In a series of studies, Lubinski and colleagues (Park et al., 2007, 2008; Robertson et al., 2010; Wai et al., 2005) showed that creative accomplishments in academic (degrees obtained) vocational (careers) and scientific (patents) arenas are predicted by differences in ability. These researchers argue that previous studies have not found a relationship between cognitive ability and creative accomplishments for several reasons. First, measures of ability and outcome criteria did not have high enough ceilings to capture variation in the upper tail of the distribution; and second, the time frame was not long enough to detect indices of more matured talent, such as the acquisition of a patent (Park et al., 2007).
- Dai, D. Y. (2010). The nature and nurture of giftedness: A new framework for understanding gifted education. New York, NY: Teachers College Press.
- Lubart, T. I. (2003). In search of creative intelligence. In R.J. Sternberg, J. Lautrey, & T. I. Lubart (Eds.), Models of intelligence: International perspectives (pp. 279–292). Washington, DC: American Psychological Association
- Park, G., Lubinski, D., & Benbow, C. P. (2007). Contrasting intellectual patterns predict creativity in the arts and sciences: Tracking intellectually precocious youth over 25 years. Psychological Science, 18, 948–952. doi:10.1111/j.1467-9280.2007.02007.x
- Park, G., Lubinski, D., & Benbow, C. P. (2008). Ability differences among people who have commensurate degrees matter for scientific creativity. Psychological Science, 19, 957–961. doi:10.1111/j.1467-9280.2008.02182.x
- Robertson, K. F., Smeets, S., Lubinski, D., & Benbow, C. P. (2010). Beyond the threshold hypothesis: Even among the gifted and top math/science graduate students, cognitive abilities, vocational interests, and lifestyle preferences matter for career choice, performance, and persistence. Current Directions in Psychological Science, 19, 346–351. doi:10.1177/0963721410391442
- Wai, J., Lubinski, D., & Benbow, C. P. (2005). Creativity and occupational accomplishments among intellectually precocious youths: An age 13 to age 33 longitudinal study. Journal of Educational Psychology, 97, 484–492. doi:10.1037/0022-0663.97.3.484
The re-analysis was by Grady Towers, with quoting and semi-philosophic speculation, as linked before. I suggested that increasing IQ might not be very useful, with the first human issue being a social contigency that your citations don't really seem to address because patents and money don't necessarily make people happy or socially integrated.
The links are cool and I appreciate them and they do push against the second (deeper) issue about possible diminishing marginal utility in mindware for optimizing within the actual world, but the point I was direct...
The failures of phlogiston and vitalism are historical hindsight. Dare I step out on a limb, and name some current theory which I deem analogously flawed?
I name artificial intelligence or thinking machines - usually defined as the study of systems whose high-level behaviors arise from "thinking" or the interaction of many low-level elements. (R. J. Sternberg quoted in a paper by Shane Legg: “Viewed narrowly, there seem to be almost as many definitions of intelligence as there were experts asked to define it.”) Taken literally, that allows for infinitely many degrees of intelligence to fit every phenomenon in our universe above the level of individual quarks, which is part of the problem. Imagine pointing to a chess computer and saying "It's not a stone!" Does that feel like an explanation? No? Then neither should saying "It's a thinking machine!"
It's the noun "intelligence" that I protest, rather than to "evoke a dynamic state sequence from a machine by computing an algorithm". There's nothing wrong with saying "X computes algorithm Y", where Y is some specific, detailed flowchart that represents an algorithm or process. "Thinking about" is another legitimate phrase that means exactly the same thing: The machine is thinking about a problem, according to an specific algorithm. The machine is thinking about how to put elements of a list in a certain order, according to the a specific algorithm called quicksort.
Now suppose I should say that a problem is explained by "thinking" or that the order of elements in a list is the result of a "thinking machine", and claim that as my explanation.
The phrase "evoke a dynamic state sequence from a machine by computing an algorithm" is acceptable, just like "thinking about" or "is caused by" are acceptable, if the phrase precedes some specification to be judged on its own merits.
However, this is not the way "intelligence" is commonly used. "Intelligence" is commonly used as an explanation in its own right.
I have lost track of how many times I have heard people say, "an artificial general intelligence would have a genuine intelligence advantage" as if that explained its advantage. This usage fits all the checklist items for a mysterious answer to a mysterious question. What do you know, after you have said that its "advantage" is "intelligence"? You can make no new predictions. You do not know anything about the behavior of real-world artificial general intelligence that you did not know before. It feels like you believe a new fact, but you don't anticipate any different outcomes. Your curiosity feels sated, but it has not been fed. The hypothesis has no moving parts - there's no detailed internal model to manipulate. Those who proffer the hypothesis of "intelligence" confess their ignorance of the internals, and take pride in it; they contrast the science of "artificial general intelligence" to other sciences merely mundane.
And even after the answer of "How? Intelligence!" is given, the practical realization is still a mystery and possesses the same sacred impenetrability it had at the start.
A fun exercise is to eliminate the explanation "intelligence" from any sentence in which it appears, and see if the sentence says anything different:
Another fun exercise is to replace "intelligence" with "magic", the explanation that people had to use before the idea of an intelligence explosion was invented:
Does not each statement convey exactly the same amount of knowledge about the phenomenon's behavior? Does not each hypothesis fit exactly the same set of outcomes?
"Intelligence" has become very popular, just as saying "magic" used to be very popular. "Intelligence" has the same deep appeal to human psychology, for the same reason. "Intelligence" is such a wonderfully easy explanation, and it feels good to say it; it gives you a sacred mystery to worship. Intelligence is popular because it is the junk food of curiosity. You can explain anything using intelligence , and so people do just that; for it feels so wonderful to explain things. Humans are still humans, even if they've taken a few science classes in college. Once they find a way to escape the shackles of settled science, they get up to the same shenanigans as their ancestors, dressed up in the literary genre of "science" but still the same species psychology.