So far we have discussed what contributes to our ideas of ‘abnormality’ and these issues have been illustrated by examining the real-life example of dyslexia.
We will now consider the different potential explanations that have been offered to account for the observed symptoms of dyslexia.
Uta Frith (1999) has provided a useful framework for thinking about the nature of developmental difficulties.
Frith suggests that there are three main perspectives on any given developmental condition: a behavioural, cognitive and biological one.
In addition to this there are environmental factors (literally referring to the environments, biological or otherwise, that we are exposed to) that can have a role in the accounts offered from these perspectives.
• Behavioural perspectives provide a model of the difficulty by describing the nature of the behavioural symptoms experienced, much as we have done in modules 1 and 2.
• Cognitive perspectives describe what mental processes are involved in and affected by the difficulty (e.g. memory, perception, attention). As such, these descriptions offer a cognitive ‘explanation’ of what may cause the types of behavioural symptoms observed.
• Biological perspectives offer descriptions of the behavioural difficulties in terms of their potential biological origins, which can cover genetic, biochemical and neurophysiological explanations.
Thus, biological and cognitive perspectives offer theoretical explanations that require experimental validation, whereas behavioural perspectives tend to be less debated because the behaviours can be directly observed.
Cognitive perspectives describe cognitive processes that might explain how the biological and behavioural accounts map onto each other.
For example, damage to one area of the brain (biological perspective) may result in an inability to store new long-term memories (behavioural perspective), because the person is no longer able to transfer information from short-term to long-term storage (cognitive perspective).
Frith's framework echoes the extent to which perspectives in psychology can be seen as complementary, conflicting and co-existing.
It also suggests that, when discussing explanations of ‘abnormal’ development, it is wrong to think that biological and cognitive perspectives are competing with each other.
In fact, cognitive and biological models can be complementary rather than conflicting.
We can use this framework to think about theoretical explanations of dyslexia.
As we have already provided a behavioural account of dyslexia in module 1 and 2, we will now consider cognitive and biological explanations of what may cause these behaviours and acknowledge environmental influences on their development.
After examining each explanation individually we suggest how different perspectives can be put together to offer a complete account.