"Belonging" è il termine usato in psicologia e credo che sia appropriato in questo contesto
"Belonging includes the person's fit with his/her environments and also has three sub-domains. Physical Belonging is defined as the connections the person has with his/her physical environments such as home, workplace, neighbourhood, school and community. Social Belonging includes links with social environments and includes the sense of acceptance by intimate others, family, friends, co-workers, and neighbourhood and community. Community Belonging represents access to resources normally available to community members, such as adequate income, health and social services, employment, educational and recreational programs, and community activities."
http://www.gdrc.org/uem/qol-define.html

My degree in psychology is pretty old now, but I think I can safely say that to belong to a group pschologically speaking is to identify with it and vice versa, so: "... are constructed around what you identify with and your relationships". or "... what a person identifies with and their relationships".
To use the plural "belongings" here would introduce the ambiguity of "physical belongings", clothes and things like that, rather than belonging to groups of people.