Kevin Mitchell, who writes the Wiring the Brain blog has in interesting post that examines a conundrum: if the human brain, even the adult brain, can be changed through learning by experience, does it still make sense to talk about innate traits?
Mitchell considers the conundrum with examples in autism, dyslexia and dyscalculia. He suggests that effective early interventions can break the vicious cycle in which innate tendencies reduce the opportunities for experience to change the brain's wiring. Read the whole post here.
Though less widely known, dyscalculia (a selective difficulty in mathematics) is equally common and shares many characteristics with dyslexia. The initial problem is in innate number sense – the ability to estimate and compare small numbers of objects. This faculty is present in very young infants and even shared with many other animal species, notably crows. Formal mathematical instruction is required to build on this innate number sense but also crucially relies on it. As with reading, mathematics requires hard work to learn and if numbers are inherently mysterious then this will change the nature of the child's experience, lessen interest and reduce practice. At the other end of the spectrum, those with strong mathematical talent may gravitate towards the subject, further amplifying the differences between these two groups.
Thus, while a certain type of experience can alter the innate tendency, the innate tendency makes getting that experience far less likely. Brain plasticity tends instead to amplify initial differences.