2.3 Biological explanations of dyslexia
Some physical characteristics appear to be ‘typical’ of people with reading difficulties, although their relevance is debated. These include being male, tendencies towards left-handedness or mixed-handedness (i.e. inconsistency of hand preference across different tasks), and a variety of neurological 'soft’ signs and minor physical anomalies. We will consider each of these in detail in the sections that follow. There is also some evidence that people with dyslexia (and their relatives) may show higher rates of allergic conditions such as asthma and eczema as well as other autoimmune disorders. On the surface these factors may appear to have little to do with dyslexia. However, by relating these physical characteristics to the observed behavioural symptoms of dyslexia we may identify clues to the possible biological mechanisms underlying the condition.