Competence & Motor Apraxia
Have you ever thought about how we decide whether a person is 'high' or 'low' functioning?
A huge percentage of how this is assessed relies on purposeful motor output and not true cognitive ability.
For example, some early tests of cognition require a young child to hold and bang a toy, turn or move their body to look for a fallen fallen toy or shake and ring a bell. These motor actions are used by assessors to establish a best guess about the child's cognitive level or "brain age"... but there are many issues with this type of assessment tool.
We also do this with an adapted version of the 'walnut shell game' played at carnivals around the world. A shiny object is placed under a shell on the left and then quickly adjusted so that it is under a different shell on the right.
This fun game requires a lot from an individual: being able to orient to narrow set of information in the environment, to organize both eyes to work together and follow a moving object, sit or stand still at a table (and have the resources to concentrate on something other than your posture), process spoken language, keep part of your body still in space while reaching with your arms, grasp the shell and pull it away. We expect individuals to correctly point to and identify which shell has the object under it and make assumptions on the person's competence if they are incorrect. But rarely do we consider that other things might be happening with the individual's body that is not related to their cognitive competency.
A body of research that started with Elizabeth Torres shows us that motor apraxia is distinctly different to classic dyspraxia or developmental coordination disorder, Motor Apraxia is a sensorimotor difference that prevents people from reliably producing purposeful motor actions. It is tricky to identify because sometimes people with motor apraxia can complete very sophisticated and complex movements. These movements lead many people to say things like "but she did it yesterday"..."I know you can do it!"..."He just doesn't want to."
BUT the difference between purposeful and planned movement and these spontaneous movements is which part of the brain is being used. Spontaneous complex movements and thoughtful intentional movements are completely different.
Before you judge a person's "developmental ages", or cognitive ability, please think twice. Sometimes a person's body does not reflect their desires or thinking. Externally observed actions and behaviors do not reliably indicate internal states of mind and intent.