When I was at school, around year 4 or 5, I used to ‘read’ people’s personalities by rummaging around the contents of their pencil cases. Erasers signified a comfortable admission to making mistakes, white-out was insecurity, possessing neither was strength of character. Due to our age, those with pens were more confident and grown up than those with pencils. A dozen pens/pencils was eclectic, a few was ease. The shape, size and style of the actual pencil case led to fashion victims and practicality.
These days I find that bedrooms provide a similar insight in to people.