Unweaving the rainbow of human sexuality: A review of one-night stands, serious romantic relationships, and the relationship space in between

For 50 years, relationship researchers have primarily focused on two varieties of relationships; one-night stands and serious romantic relationships. Both of these are treated as (1) distinct relationships and (2) a comprehensive list of the relationships people of any sexual orientation engage in. However, over the last 10 years this apparent simplicity has been called into question; researchers have revealed a rainbow of potential relationships that individuals can and do engage in. From this perspective, relationships may act as “compromises” between two extremes (i.e., pure monogamy or pure zero-acquaintance sex) and are negotiated in the course of relationship development. Relationships then reflect different levels of short-term mating and long-term mating aspects simultaneously. In this review, we examine research on one-night stands, serious romantic relationships, booty-call relationships, friends-with-benefits, swinging, and polyamory. Throughout, we highlight the utility of evolutionary models to account for behaviors and patterns in these relationships and discuss the importance of an unbiased and unabashed look at the sex lives of people.