Social psychologists have argued that people are more motivated by avoiding bad outcomes than pursuing good ones. But research in my lab suggests that when deciding whether to invest in a relationship, people may be more strongly influenced by rewards (e.g., intimacy) than threats (e.g., rejection). I will describe research showing that people regret missed relationship opportunities more than rejections, stay attached to ex-partners who are rewarding rather than safe, and are more likely to stay together in the long term with partners who offer reward. I will provide evidence that the rewards of relationships may be so enticing because they are mediated by the release of endogenous opioids. Finally, I will argue that avoidantly attached individuals actively defend against social reward and discuss research suggesting that communicating love to avoidants with highly active nonverbal messages may be one way to work past these defences.