Kanhef said:
With enough research, helped by the records from the Glow and military base, a new strain could be developed that increases brains more than muscles and doesn't cause sterility. With substantial benefits and no real drawbacks, many people would make the transition willingly, achieving the goal of changing humanity to survive in a harsher world.
As pointed out by Snowguy, FEV by its very nature is going to make a person sterile. The only way you could really change that is to alter the way it works in such a fundamental way that it'd really be something completely different.
No matter whether or not it increases brain functions and muscles, or even doesn't cause sterility, changing into a big, green mutant is enough of a drawback by itself for me, personally. And anyways, humanity seemed to be doing a fine job picking things back up and surviving in the wasteland without the forcible change into a big dumb mutant. Trade was flourishing, large towns were being established, governments were forming. It may be valid to suppose that humanity was just on track to end up back where it was, making the same mistakes, that's rather presumptuous, and I'd say the Master's plan, complete with violent, forcible change to what he perceived was "better" (and the elimination of anything else) was more exemplary of humanity's mistakes than anything else present in the wasteland.
Snowguy said:
K, first off, all strains of FEV are designed to increase intelligence.
I don't believe that's true. If I remember correctly, the last strain of FEV developed just before the bombs dropped was noted for being more effective in every way
except that intelligence seemed to be either unaffected or actually reduced in subjects. Or it may just have been that the increase in intelligence only happened in more "primitive" subjects, and that as they moved up to complex mammals, including humans, its effect on the brain was markedly different. I'll have to check the FO Wiki and see if I can find that part, or perhaps I still have a save with that holotape from the Sierra Army Base (or was it the Glow?).