>>11875005Heritability of iq increases with age, rearing environment could in theory artificially boost cognitive function. While you age you begin to move away from these artificially enriched environments, select into more suitable less challenging environments, and are likely subject to early senescence and neurodegenerative processes begin to take hold. Fluid intelligence also peaks somewhere between 17-21 its entirely possible for it to peak earlier. Did you play any contact sports as a child? That could be a factor if you were suffering repeated head trauma. Did you smoke marijuana or abuse alcohol extensively as an adolescent? this can also be a factor. how was your sleep and diet during puberty? All of these things can affect adult cognitive function. the thing about heritability increasing is murky, but I really do believe that you are reduced to raw genotypic potential in adulthood.
