When your kid comes home and announces "Mommy, Stella hit me today!" it's tough to fight the urge to go all mama-bear. Before you do, ask this simple question: What happened right before she hit you? ("Well, um, I pulled her hair but only because I wanted her red crayon and she wouldn't give it to me!") Then walk through the situation with her and discuss ways they each could have acted. "The part of the brain that regulates social skills just isn't developed in a 4-year-old," says Abigail Baird Ph.D., a scientist, researcher and Associate Professor of Psychology at Vassar College in Poughkeepsie, NY. "Until then, parents have to act as external frontal lobes for their kids. As the adult, it's your job to try to help your child see the bigger picture."