I believe the answer is: Durkheim
In durkheim's social solidarity model, social solidarity is divided into mechanical solidarity and organic solidarity.
The mechanical solidarity is created by following a same tradition/ritual as a member of a certain social group, while organic solidarity is created through the division of labor.
You and your friend would be creating a partnership.
Ottoman Empire: 3
Holocaust: 4
Zionism: 2
Anti-Semitism: 1