Humans evolving into hyper-intelligent beings is a powerful idea in science fiction, but that's probably where the idea will have to stay. Our brains have reached an evolutionary "sweet spot," and we can't get much smarter without making major trade-offs.
That's the finding of psychologists Thomas Hills of the University of Warwick and Ralph Hertwig of the University of Basel. They have examined a number of studies, and they have come to one inescapable conclusion: there's a steep price to pay for enhanced brainpower, and it's almost certainly not a good deal from an evolutionary perspective.
They point to how groups of people with enhanced cognitive abilities — including "savants, people with photographic memories, and even genetically segregated populations of individuals with above average IQ" – and these groups generally suffer from much higher rates of cognitive disorders like autism, extreme synesthesia, and other neural disorders. The researchers also point to attention-focusing drugs like Ritalin, which can really help people with ADD but can actually decrease performance when taken by people with normal attention spans.
If the zombies are indeed breeding us to have better tasting brains, they're in for some kind of disappointment.