Why does the primary somatosensory area have a larger section dedicated to the fingers and hand, than to the feet and toes?

Because of the evolutionary process.

Explanation:

This result can be explained using the evolution theory. Since we came down from trees and started walking on two feet and using our hands in various tasks, using tools, catching, interacting with each other, this situation resulted in an environment and routine where we use our hands and the sensory feedbacks that we get from them much more often than we do with our feet. Therefore the evolution gave the priority to the hands and fingers because they were more critical in the progress of our species.

I hope this answer helps.

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