Friendship as a Social Institution

What is the social organization of love, friendship, rivalry, marriage, admiration, collegiality, parenthood, acquaintance, and clientage? How are these types of relationships similar and how do they differ? Few sociological works exist on relationships between friends, business partners, customers and clerks, mailmen and homeowners, and employers and employees, as social rather than role relationships. This classic book remains of interest because it focuses on voluntary personal relationships