Dr. Becky, a clinical psychologist, believes sibling rivalry isn't necessarily a problem. It's a training ground for lifelong ...

To continue reading this content, please enable JavaScript in your browser settings and refresh this page. Whether they’re arguing over the last cookie, a favorite ...

If you’ve ever watched a pair of siblings laughing over an inside joke, backing each other up at the dinner table, or navigating life with the seamless shorthand of best friends, you might assume it’s ...