Grouping Knowledge

Human beings like to categorize stuff. We sort things alphabetically and by color. We notice differences in size, shape, and texture. We differentiate between salty and sweet, loud and quiet, hard and soft. Give a little child a bag of toys and it won't be long before she organizes it according to some kind of system. It might be as simple as "toys I like" and "toys I don't like" but still...it will be sorted.