You've probably heard these exact words before. You might have even said it about a friend or sibling. But all it takes is a couple kids playing together. One grabs the other's toy or gets a little too close for personal space. A little pushing, a little shoving, A few snarky words are said. The volume rises, and then Mom or Dad asks what the problem is. The aggrieved response is: "He did it first!" Oftentimes the parent will tell the children that they need to work it out, not tattle on each other, and shake hands. The handshaking is all about timing because you don't want to be the first to make a move toward concession. So on cue, hands meet, apologies are mumbled, and the kids start playing again maybe a little awkwardly at first. We may be more sophisticated than a couple kids, but our relationships have their share of tension. We've also had many more years to build up our store of biases and opinions about the way things should be. We disagree. Wo...