Why is the psychosocial dimension so important in mediating self-determination conflicts?

In this video, Marie-Joëlle Zahar explores what happens when a mediation process is treated as transactional, when the claims of a group seeking self-determination and their historical grievances are dismissed and emotions that emerge in the process (on either or all sides of the conflict) are ignored or suppressed in order to broker a deal. She concludes that mediators need the skills to engage with empathy and allow parties space and time to tell their stories, while encouraging them to envision futures that would look better for all parties involved.