Recently I've reviewed a comprehensive reanalysis of the IHDP (Infant Health and Development Program) which concluded that failure to raise the g (general intelligence factor) does not account for the fade-out effect so commonly seen with the majority of these intervention programs. This conclusion was reached based on the finding that during the intervention, g was in fact raised. The degree to which g is malleable (if only in childhood) I cannot be sure. What didn't add up for me was the idea that g would be malleable for children only, and then would decrease by mechanism of "settling" into true genetic potential; especially since g represents essentially the same construct across ages, races, and genders. What we do know is that unused neural synapses are eventually lost, a sort of "use it or lose it" phenomenon; this as I'm sure you know is synaptic pruning. I suggest that it is not the genetic nature of g and IQ that is increasing, but rather synaptic pruning is occurring to different magnitudes between individuals and groups. That it would occur differently between individuals is obvious of course; however agreeing upon a theory for groups is a bit more complex. One explanation for the fade-out effect seen in IHDP is that once returned to their original environments, participants simply did not select into environments of higher stimulation. I propose on the contrary, they simply were unable to select; and perhaps even prevented. We know that the vast majority (though not all) of the children who participated were of a low socio-economic background; and for this reason it is entirely plausible that cognitively demanding environments simply were not readily available to them. By the time black participants entered school, neurally stimulating activities were probably even discouraged (if you know anything about the anti-educational peer culture, then you understand what I mean) by not only teachers with low expectations, but peer groups as well. These are factors which would prevent selection into improved environments, especially as a child ages. Poverty itself provides few opportunities for such selection to occur in the first place. One could argue that participants had lower amounts of genetic potential to begin with, and that they simply regressed towards this potential. It is true that the abecedarian approach used in IHDP did not fully address the medical needs of LBW (low birth-weight) infants, but if we assume also that low IQ leads to poverty, we would expect most participants to regress. MOST, but not all. Because all of the participants regressed, regardless of socio-economic status, it suggests that the mechanism for the regression may not actually be genetic. We would expect higher SES participants to maintain some, if not all gains, due to higher inherent potential. No such finding has been reported. I concede that I do not know the exact ratio of poor to high ses participants, however. Perhaps it is possible for one to, in effect, lose genetic potential outside of the right environmental conditions. To clarify, I do not argue that the entire gap between blacks and whites is explained by this mechanism; (at most five points, the usual size of gains found by these projects, ranging from 4.4-5) or that with the right environment, everyone can become a genius. I acknowledge accordingly that individuals have varying amounts of genetic potential, and perhaps even groups (some studies have reported differing levels of white and grey matter between racial groups, as well as differences in brain size and neural allele frequencies, though to the degree that this contributes to the IQ gap I am unsure). At best we can conclude from these differences that different ethnic groups think and view problems differently, though to deem one way of thinking as inferior is a stretch at best, closed-minded at worst. Many intervention studies have been successful in reducing behavioral complications, improving life outcomes and academic performance, all independent of IQ gains which faded over time. The original abecedarian saw a permanent gain of 5 points, a significant difference which was accompanied by some behavioral improvements. This suggests to me that culture and parental values are better predictors for such than IQ scores. At least 10 points of the gap can be concretely explained by low SES (eliminating poverty depressors raises the black mean by 5 points, or 1/3), and parental values/education (directly related to culture, accounts for another 5 points, we know this because this is the size of the gains found by intervention studies, which introduces activities and learning methods unlikely to be found in the households of less educated parents, and dare I say; black parents in general, regardless of education). The final 5 points is left up to non-home environment (school, peer groups and teachers), neighborhood quality and genes. Some sources report that the gap has decreased by 1/3, the validity of this claim I am not certain. If this is true, it is difficult to determine the direct source of this gain; perhaps integration and higher overall SES for blacks is the cause. In conclusion, it seems that g isn't as immutable as previously thought, a finding that is in direct contrast with the theory of increased genetic influence. My argument is that increasing IQ scores are not relevant to the reduction of social ills, and that the imperfect correlation between IQ and academic performance suggests not that those with lower scores will always exhibit worse performance, but rather that those with higher scores should always exhibit better performance. In other words; higher scores may predict better academic performance, but lower scores do not always predict poor academic performance. The genetic potential of black americans, though it may in fact be lower than 100, is not certainly not 85 as I have demonstrated above. I argue also, that the fade-out effect is synaptic pruning resulting from the temporary nature of the interventions, rather than a failure to cause true gains in the first place. Some Head Start gains have been kept for white participants, and perhaps this represents more readily available opportunities for cognitive stimulation in white communities and culture. I argue also that anti-educational culture is a mechanism by which synaptic pruning acts against valuable neural connections, because they have become neglected. East Asian culture by reverse provides abnormally high neural stimulation. Gains seen in interventions may not be as hollow as previously thought, because behavioral improvements are usually maintained. Both the Flynn Effect and IHDP show that abstract reasoning can increase or decrease by non-genetic means. Lastly, I think abstract reasoning, or g should be viewed the same way we view singing, or dancing. Some individuals possess natural aptitude, while others gain their skill through training and practice. Many people would say that Michael Jackson had "natural rhythm". That doesn't mean that others can't be good with choreography, or that their increases in skill are hollow and not real. I hope that my analogy will provoke some thought. The human brain is an amazing and vastly misunderstood organ, and I believe it deserves much less of the oversimplification it tends to receive in many HBD circles. To close: If only the genetically gifted had hope of ever obtaining success, no one else would bother to practice.Results are what matters, and if interventions are showing us that academic achievement and social ills can be improved upon without improving IQ and/or g, then we must question the relevance of continuing to study the IQ gap. Notes: Differences between the control group and the recipients of the abecedarian intervention were found as early as six months, however this is still significantly after the initial intervention began (six weeks) which leaves the possibility that the differences were the direct result of the program. Designers of the intervention claim to have controlled for small sample sizes and mother's IQ, finding no diminished impact. -If anyone could provide me with some extra data citing more behavioral improvements that would be great, I've read over a lot of studies that showed improvements across different measures and to different degrees, but to form a coherent picture I'd need more information. Thank you so much! Sources: http://www.johnprotzko.com/wp-content/uploads/2014/12/Protkzo-2016.-raising-IQ-raising-g-and-fadeout.pdf https://www.sciencedaily.com/releases/2016/03/160314151645.htm https://en.wikipedia.org/wiki/Synaptic_pruning http://www.promisingpractices.net/program.asp?programid=132 -SFS
I think Table 6 on Page 467 (or 7/14 for the pdf file) is where the claims are coming from; if you look at the very bottom of the chart, it appears to suggest that the SO group, or Sokoto Nigerians, are the least genetically dissimilar from CH (Chimpanzees) out of the groups. Of course the rest of the chart also demonstrates how generally similar all human ethnic groups are to each other; still, what are the implications of this data from a genetic perspective?