This is based on a press release about an article that hasn't even passed peer review yet, itself about a small-n animal study that hasn't been replicated. Mean

This is based on a press release about an article that hasn't even passed peer review yet, itself about a small-n animal study that hasn't been replicated. Meanwhile, in peer-reviewed human research, there have been massive genome-wide association studies (GWASes) in which tens of thousands of human genomes have been scanned for behavioral traits of interest, including IQ, it has been found that NO single-gene variant has a strong effect on IQ. That is none. There simply isn't any common gene variant in humankind that has a large effect on IQ, and there aren't even any rare variants of large enough effect to show up in lineage studies or in GWASes or in any other human genetics investigation on the topic of IQ. Meanwhile, human investigations of identical twins brought up in separate households, including a striking recent case in Colombia of two pairs of twins in which one twin from each pair ended up with the other twin's family to be brought up,[1] continue to show that identical (monozygotic) twins tend to resemble each other more than siblings typically do, even if raised apart, but also can differ from each other in a variety of ways, including in IQ, and especially in IQ if they are not brought up in the same household. Environment always matters in human development, for every trait. That's called the Third Law of Behavior Genetics.[2] After edit: Here is a link[3] to a description of the Morris Water Maze test, which this press release says was used in the study trumpeted to the press here. I'd like to see how the variance in performance of their study mice compares to mice used in previous studies with the water maze as a criterion variable of mouse intelligence, as there have been many, many studies like that. [1] http://www.nytimes.com/2015/07/12/magazine/the-mixed-up-brothers-of-bogota.html http://www.nytimes.com/2015/07/12/magazine/the-mixed-up-brot... [2] http://cdp.sagepub.com/content/9/5/160.abstract http://cdp.sagepub.com/content/9/5/160.abstract http://cdp.sagepub.com/content/24/4/304.full http://cdp.sagepub.com/content/24/4/304.full [3] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2895266/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2895266/