Although parents don’t always think about their extended family tree when they are thinking about why their son or daughter is having trouble in school, it’s important that they should. It’s a rare teacher or doctor who will think to ask about whether a child’s learning problems or “underachievement” runs in the family, and if parents or grandparents don’t think about it, it may be highly likely that no one will. In addition to individual inherited factors contributing to giftedness and learning disability, assortative mating (tendency of like to marry like) can dramatically increase the likelihood of adults’ learning differences being inherited by children (6-40x) higher chance of a person with a reading disability marrying another with a reading disability!
In the past 30 years, there have been dramatic advances in our understanding of how dynamic pathway remodeling exists in the brain. Partially redundant systems help us to accurately sense our environments, learn and remember, and plan and act. Partial redundancy provides a buffer system in the event of injury; if one system is injured, another increases its activity to take its place. Scientist found that the part of the brain that normal hears in congenitally deaf subjects was reorganized to ‘see’ – so although the deaf were unable to hear, their visual sensitivity was greater than normal hearing subjects because more brain resources were now devoted to seeing.
It is likely, then that some twice-exceptional abilities many occur, as the result of the brain’s compensatory drive from a deficit or injury. One practical implication for this idea is that a thorough search for strengths and gifts should be made in the setting of any disability. But in some cases, there is a suggestion that some disabilities or delays in development are secondary to gifts. In a study from Port Townsend (Sweetland), researchers found that the higher the IQ, the greater the likelihood of high VIQ/PIQ discrepancies (17% of a control sample had IQ sub-test discrepancies of 18 points or more vs. 55% of a gifted sample). And there’s that data from Giedd and colleagues showing that the higher the IQ in young children, the slower the development of prefrontal cortical thickness. Extreme ability or talent may result in slower time courses of development or stunting of other systems or pathways if resources are limited.
Different developmental time courses should also (in the best of all worlds) warrant appropriate curricular and other educational accommodations. For instance, if young gifted children were found to present as mixed dominant “late-bloomers”, shouldn’t demands for heavy bihemispheric activities be individualized (e.g. note-taking, writing, to open-ended prompts) and instruction optimized for what we know to be well developed?