Bridging across lines of difference is challenging.  How can American universities play a role in creating a more bridged America?

Bridging is when someone builds a meaningful relationship across lines of difference.  What skills must one posses in order to bridge?  What are the positive impacts of a more bridged society?  

For as long as we have been on this earth, humans have separated into groups based on perceived similarity.  With this behavior wired into our DNA, we continue to find ways to divide.  How have laws in America exploited this biological behavior?  How separate are we?  What are the consequences if these separations persist?