• Rebecca Watson wrote a new post, The Weird Way That Learning About Your Genes Can Change You, on the site Skepchick 1 year, 4 months ago

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    I’ve made a few videos about genetic testing, most of which involve me sort of defending it being open to the general public. To sum up, I t […]

    • Yeah, you’d be surprised at the defense of genetic determinism, even from people who really should know better. (And yes, if you say “a gene for X”, I’m going to demand a protein for X as well, not just a weak correlation.)

    • Psychological effects are likely major mechanisms for effects that are considered to be ‘genetic’ via GWAS; very likely mediated through the effects of ethnicity on social status, discrimination and then correlate via SNPs of ethnicity.

      The major statistical method used in GWAS is what is called the ACE model. That model imputes that phenotype is a purely linear and purely additive function of SNPs, environment, and noise. The model specifically imputes that variance due to interactions between different SNPs and environment; SNPi X SNPj and SNP X environment effects are exactly zero. We know that they are not zero, we know there are very strong gene X gene effects (transcription factors are products of genes, transcription *has to* be sensitive to transcription factors). Ignoring this real source of variance and imputing that all variance is purely (and linearly) associated with SNPs generates what is called ‘phantom heritability’.

      If you are a member of an ethnicity which is ‘believed’ to be inferior, why wouldn’t that have the ‘placebo effects’ as observed in the OP study?

      If ‘traits’ of different ethnic groups ‘correlate’ with those ethnic groups because of the ‘conventional thinking’ of whole populations, why wouldn’t people with those ethnicity have ‘traits’ that social peer pressure imputes people of that ethnicity to have? GWAS would then be able to associate SNPs of the ethnicity with the trait; even though the trait is purely a social phenomena and has nothing to do with any genetic causation. The causation is by the social environment.

      I am pretty sure that virtually all of the ‘findings’ of GWAS are due to this effect; they are due to the flaws of the ACE model, not due to any genetic ‘causation’ of the trait. If a trait is ‘important’, then it is ‘too important’ to be ‘set’ by genetics. It has to be set by development, so that the organism can adopt how much, or how little of the trait is necessary, based on what would be better, in the particular environment the organism finds itself.