Many projects encounter difficult project relationships but techniques from positive psychology offer a new way of designing and delivering projects in a way that facilitates positive emotions and good relationships. Positive Psychology provides some well researched, evidenced based techniques that you can use to increase the chances of your project being successful.
According to Seligman, Positive Psychology has three central concerns: Positive Emotions, Positive Individual Traits, and Positive Institutions. All of these offer ways for project managers to help improve project relationships.