I found the whole article fascinating, but my favorite quote was:
“I think these may become landmark findings, forcing us to ask whether these acting-out kinds of problems are secondary to the inappropriate maturity expectations that some educators place on young children as soon as they enter classrooms,” said Sharon Landesman Ramey, director of the Georgetown University Center on Health and Education, who was not connected with either study.
One of the reasons I love my daughters' school (Pathfinder K-8), is because the teachers have appropriate maturity expectations for the children in their classes. The expectations are not low --- in fact I think they are quite high --- but they are appropriate and grounded in research on what is developmentally appropriate for small children.
For example, the kids in the Bat clan (my daughter's Kindergarten class), are expected to show respect and kindness towards each other and towards the teacher (the fabulous Kelly Riggle Hower), which in my opinion is one of the most important thing kids can learn in the first year of school. There are consequences for not treating others well, but, as my daughter says, "Kelly is not mean when she tells kids to stop." Kelly does not belittle children for their behavior, use shame to attempt to control behavior, label them, or, as is frequently the case in other classes I have observed, take away recess time as a consequence, since what many of these children desperately need is a chance to get their energy out and move their bodies around.