In this chapter, we review the most recent research on sacrifice in romantic relationships, emphasizing the crucial role that sacrifice plays in optimal relationship development and maintenance. Sacrifice is defined as forgoing immediate self-interest and incurring costs to the self—either by giving up something desirable, such as time or money, or by doing something undesirable—in order to benefit their romantic partner. We review research showing that the willingness to sacrifice can convey that partners are invested in and care about their relationships. We show that approach-motivated sacrifices often have positive consequences, whereas sacrifices made for avoidance motives often have negative consequences for both giver and recipient. Given that when partners make sacrifices for each other, they are likely to experience some negative emotions due to incurring personal costs, it is not beneficial to try to suppress or conceal these emotions from one’s partner, as suppression is associated with poorer relationship quality as reported by both members of the couple. We conclude the chapter by discussing future directions for research on sacrifice, including research on the temporal component of sacrifice as well as individual variation in how people make the decision to sacrifice for a romantic partner.

Sexuality is a key factor that distinguishes and shapes romantic relationships. In this chapter, we present evidence demonstrating the importance of sexuality in romantic relationships with a particular focus on the ways in which sex can positively impact such relationships. To this end, we describe the role of both sexual frequency and sexual satisfaction in shaping relationship quality. We also review research that sheds light on how couples can stave off declines or changes in sexual desire over time, as well as maintain sexual satisfaction during times when they have conflicting sexual interests. To this end, we focus our attention on understanding the motivational and cognitive influences important to the maintenance of desire and sexual satisfaction over time, as well as the individual differences and relationship factors that contribute to satisfying sexual relationships. We then conclude the chapter by highlighting what we see as promising directions for future research on sex and relationships.