I'm in the middle of Po Bronson & Ashley Merriman's Nurture Shock (thanks for the recommendation, Abbie!) and it is SO great. Fascinating. I'll have to type up my notes when I'm done, but for now I want to jot down this quote from the book:

Preschool and elementary school teachers proclaim tattling to be the bane of their existence. One of the largest teachers' training programs in the United States ranks children's tattling as one of the top five classroom concerns -- as disruptive as fighting or biting another classmate.

But tattling has received some scientific interest, and researchers have spent hours observing kids at play. They've learned that nine out of ten times a kid runs up to a parent to tell, that kid is being completely honest. And while it might seem to a parent that tattling is incessant, to a child that's not the case -- because for every one time a child seeks a parent for help, there were fourteen other instances when he was wronged and did not run to the parent for aid.

When the child - who's put up with as much as he can handle - finally comes to the tell the parent the honest truth, he hears, in effect, "Stop bringing me your problems!" According to one researcher's work, parents are ten times more likely to chastise a child for tattling than they are to chide a child who lied.