The Etiology of LD

It's not difficult to understand the skeptic’s point of view as to the reality of LD as an actual disorder.  Skeptics have suggested that behaviors associated with LD could have been the result of a number of environment conditions, rather than some innate cause. For example, troubles with reading could simply have been attributed to lack of exposure to print at an early age, or students' lack of motivation, or student dispositions toward reading. In other words, it could easily have been argued that environmental conditions are just as plausible a reason for difficulties and that there is little reason to believe that child A doesn't have the same innate ability to learn how to read as child B. I’m sure I myself, and other educators I have known, have at some point in the past ascribed a child's lack of performance to his living conditions or lack of effort, rather than consider the possibility that their difficulties may actually be due to something physically taking place within the child's brain. These "causes" are so tempting to educators, and perhaps to researchers for other reasons, given how often we have seen first hand the impact a child's home life can have on their academic performance or dispositions. Perhaps the reason for suggesting that learning disabilities are the result of environment conditions rather than due to abnormalities in the physical brain may be due to the hope that improved conditions and interventions can improve the difficulties students have with learning. Attributing them to the brain is almost equivalent to admitting defeat. 

Today, however, there is evidence that neurological differences are likely to be the cause of these difficulties. That, in fact, there is something physically different about child A and child B that results in one having a more difficult time in learning to read than the other.  Although our book is a little dated given the speed of technological advance, the research done in neuroimaging, and in postmortem studies prior to this, have discovered structural and functional differences between patients with and without reading difficulties.  The evidence of heritability of disabilities provides additional evidence of the physiological cause of LD. In fact this physiological link between brain and disability seems well established, even at the time of these studies the studies in the text, Learning Disabilities: Foundation, Characteristics and Effective Teaching. It is likely that the most recent literature only confirms this link.

Although I know very little about brain development and the impact of environment on the developing brain, I wonder if there is yet still room for skeptics, even with the widespread acceptance neurological differences as the root cause of learning disabilities. Is it possible that while regional brain differences are the causes of learning disabilities, could environment factors affecting the growing child be the cause of these differences? In other words, how malleable is the growing brain? I'm aware of the concept of familiality, the greater likelihood of relatives having the learning disability, but couldn't these family members also be exposed to similar conditions causing an abnormal brain development, and subsequent disability? For example, I wonder what effects long-term dire poverty has on the development of the growing brain. Could child A have had the same reading ability as child B had he not grown up in severe poverty? An article in Science Daily, in addition to the improvement of reading ability of students with dyslexia, suggests that the brain is malleable to at least some degree, and that environmental conditions can impact brain functions. My concern isn't about the reality of LD, but rather that a sort of physiological fatalism may prevail, and that the emphasis on impersonal brain imaging may overshadow the real personal and dire socioeconomic conditions that can put children at risk of neurological dysfunction. In fact the textbook Learning Disabilities: Foundation, Characteristics and Effective Teaching only dedicates a single paragraph to environmental factors, despite this link. It make you wonder how many of these learning disabilities (as well as a host of other problems) may have been prevented, or corrected for, had more attention been directed at eradicating poverty and improving the living conditions of these children?