Richard is brave to keep knocking!  I read the Bell Curve and recommend it often. The factorial design of problems like this at a handful of factors at a handful of levels is challenging. Great Job, Lex!.,(reply>), @Darwin , it would be interesting if it were a statistical artifact, as it is so consistent and pervasive. In theory, this would indicate some sort of underlying association even if it were just an artifact itself. If that were the case, then it would mean the g factor would simply be a side indicator for the real indicator, whatever that may be. So, I would say, even if it were, the consistent correlation still points to something.<br><br>In terms of GWAS, I would be curious if it were that simple as well. I listened to a lecture a while back (I can't recall the name) that did research in sort of a biomimetics research for artificial intelligence. In his research, genetics don't appear to directly encode for neurological structure, but instead encode the growth process in time. In other words, the genetics simply encode the starting point and the process for which the final structure is built up over time. Sort of like a genetic compression if you will. If this is the case, then a simple statistical analysis of the genetics will likely fail to locate any strong correlation. This is because the real meat of the data is encoded within a time dependent physical process. As such, a physical simulation of this process is likely required to unlock that knowledge.,(reply>), @JimBob1937 That's completely fair. I'm just skeptical that the g-factor relates to anything in the material world (underpinned by alleles or at a higher hierarchical organization as you were suggesting in morphology) , as opposed to being a statistical artifact. There have been hundreds of GWAS and morphometric studies on IQ (I appreciate we should be more concerned with g-factor), and they've only discovered variants that explain a tiny fraction of the phenotypic variance.,(reply>), @Darwin , any phenotype can be altered within reason. Not all alterations are viable. Considering the structure of the brain is a phenotypical expression of genetic traits, you will be somewhat limited in how much you can alter the brain structure relative to keeping memories and such. Having a brain be a specific structure from the start is far different than trying to alter it to such a large degree well into adulthood. You seem to be drastically underestimating the complexity that goes into such tasks. With that said, I did say it is likely possible in the future given the technology, though it is likely to be limited in the ability to boost one's g factor for the aforementioned reasons. I'm a transhumanist, so I'm not foreign or against the idea of boosting human physiology via technological means. However, I would highly caution not to oversimplify the task at hand.,(reply>), @JimBob1937 g factor is a phenotype. Any phenotype can be altered.,(reply>), @Darwin , that is because IQ is an estimate of the g factor, which is liable to give an artificially low value if barriers exist. This can include psychological ones like anxiety, familiarity with the format, and other factors. Do not equate IQ with g factor. It is like arguing an exam score getting higher means your knowledge increased, even though there are many factors that could have lowered the exam score from the start, resulting in an inaccurate estimation of one's knowledge. Same applies to the g factor. I've also dabbled in the space of nootropics in the past, and currently none have shown to increase the g factor. However, concentration and other effects (like with stimulates) does increase one's ability to utilize their innate g factor. You seem to be confusing multiple concepts.