Literacy and Numeracy
Intellectual capacity, or at least some specific forms of it, seems to have become more rewarded in contemporary society than they were in the EEA. There is a positive correlation in Western society between IQ and income (Neisser et al. 1996; Gottfredson 1997). Higher levels of general cognitive ability are important not just for highly demanding, high status jobs, but also for success in everyday life, such as being able to fill out forms, understand news, and maintain health. As society becomes more complex, these demands increase, placing people of low cognitive ability at a greater disadvantage (Gottfredson 1997, 2004). While general cognitive ability may have been advantageous (and selected for) in our evolutionary past (Gottfredson 2007), numeracy and literacy represent more specific abilities whose utility has increased dramatically in recent times.
Before the invention of writing, the human brain faced no pressure to be literate. In the current age, however, literacy is in very high demand. Failing to meet this demand places an individual at a severe disadvantage in modern society. Since writing is a relatively recent invention (3500 BC) and since it is even more recently that written language has become such a dominant mode of communication, it is plausible that the human brain is not optimized for modern conditions. The fact that the neural machinery needed for writing and reading largely overlaps with that needed to produce and interpret oral communication means that the mismatch between evolved capacity and present demands is not as great as it might have been. Nevertheless, as the phenomenon of dyslexia demonstrates, it is possible to have deficits in language processing that are relatively specific to written language, possibly arising from minor variations in phonological processing (Goulandris et al. 2000). Dyslexia also appears to be linked to enhanced or atypical visuospatial abilities (von Karolyi et al. 2003; Brunswick et al. 2007). These abilities might have been useful in the EEA, but today literacy is usually more important for achieving life goals. If our species had been using written language for a couple of million years and reproductive fitness had depended on literacy, dyslexia might have been much rarer than it is.
Modern society also places much greater demands on advanced numerical skills than we faced in the EEA. In hunter-gatherer societies, numeracy demands appear to have been limited to being able to count to five or ten (Pica et al. 2004). In the modern world, one is at a major disadvantage if one cannot understand at least basic arithmetic. Many occupations require a grasp of statistics, calculus, geometry, or higher mathematics. Programming skills open up additional employment possibilities. Good logical and analytical skills create further opportunities in our information- dense, technology- mediated, and generally formalized modern society. These skills were much less useful in the Pleistocene.
The altered nature of the demands we face suggests opportunities for enhancement by readjusting tradeoffs that are no longer optimal. For example, number relations appear to be handled by brain circuits closely linked to spatial cognition of external objects and affected by spatial attention abilities (McCord 2000; Hubbard et al. 2005). Hence, enhancement of this type of spatial attention (Green and Bavelier 2006), possibly at the expense of remote or peripheral attention, could be a useful enhancement. Similarly, enhancements in reading ability at the expense of the dyslexia-related visuospatial abilities might gain support from the EOC.
-  It should be noted that IQ correlates negatively with fertility in many modern societies (Udry1978; Vancourt and Bean 1985; Vining et al. 1988). This might be an example of value discordancebetween human values and evolutionary fitness.