Board Thread:Warhammer 40k General Discussion/@comment-25686730-20141125054012/@comment-6078851-20141128164938

i'm pretty sure astartes are smarter than normal humans, maybe not in terms of their intellect directly being increased, but astartes are repeatedly mentioned as having superior senses to humans. that means things like sight, smell, hearing etc, all work better than before and as they are all directly connected to the brain - these are the things the brain gains data from - then the brain has to be working more efficiently in astartes otherwise astartes wouldn't have superior senses but would spend most of their time suffering from sensory overload - it's no use having super-sense organs if the brain can't process their information. so not necassarily an IQ boost, but in conjunction with the psycho/hypno-indoctrination, the addition of sense upgrades has to have the effect of improving the efficiency that their brains process information. ergo, smarter than humans.

plus, being smart doesn't protect anyone from doing moronic things now and then, i could point to a swathe of modern day scientists, who are generally very smart, who have truly idiotic ideas and we could all point out, and we have, the idiotic things emps has done and you don't get much smarter than him :P