This chapter deals with hate in interpersonal relationships. In the remainder of the book we will examine examples on a higher societal level, one concerning intergroup relations, but the principles of the duplex theory can relatively easily be transferred to relationships between individuals. Therefore, this chapter deals with another aspect of individual relationships that also comprises feelings of hate: love–hate. Although the combination of two seemingly oppositional concepts like love and hate appears absurd at first, daily life experiences suggest that hate and love are often quite closely connected – the ones we love have the most power to hurt us, and it can be those loved ones that stir hatred in us. Also, the mere existence of an expression like “love–hate” suggests that it must be prevalent in people's lives. Otherwise, we would not have a word for it.

Love–hate is a condition in which an individual feels intense emotions, both positive and negative, toward another. Despite the negativity, the relationship is maintained because the individuals in it receive some kind of gratification – the relationship is rewarding in some way, or is at least based on reciprocity. In fact, people not only have this kind of ambivalent relationship toward one another, but also toward things. Sweeney and Chew (2002) introduced a separate consumer–service brand relationship that recognizes the often complicated and ambivalent relationship consumers may have with services offered to them.