There is an experiment that you can do at home, in which you ask your child to make a collage (or drawing) of all the things that are the most important to them. Even better: You could ask your child to make this collage as they enter each new grade. And that will tell you the point of time at which material goods start to gain importance in your child's life.
Here's a hint: It's around seventh grade.
Hold on while I think about my seventh grade year for a moment: Never mind. I had a perm and I was in Catholic school. I was probably not a typical child.
Most children start really paying attention to their peers - and comparing themselves to them - in seventh grade. And changing what you have in life seems (for many children) to be an easy way to level the playing field.
Of course, your children will display signs of wanting things way earlier than seventh grade. I keenly recall an incident last year in which my son wanted different shoes so he could "be like other boys in his class."
But, overall, middle school is the sweet spot: It's the time when our children start picking up on parental reactions to material possessions that they will take with them through adulthood. This (of course) is just another example of how your child is always watching you - even when it seems like they are ignoring you. So now I have to think even more about the stuff we bring into our household and if they are things we need or if they are just the latest shiny toy that we want.
What kind of importance do you place on material goods in your household? Tell me in the comments.