Table 1.

Vignettes used in the study.

LantianS2	LantianRealistic	IdealCase
Paul is 30 years old and is in a relationship with Sophie for about ten years. Regrettably, he realizes that he no longer loves Sophie as much as in the early days of their relationship. He hesitates to stay in a relationship with her. Paul then goes to a doctor who recommends that he chooses one among several treatments. After having obtained Sophie’s consent, Paul chooses to take a revolutionary new treatment, under a pill form, that could improve his romantic condition by facilitating his appreciation of Sophie’s qualities. This revolutionary pill (which has been clinically tested and proven 100% reliable) intensifies the feeling of romantic love that we feel for a person. [Note: see LantianRealistic, next column over, for the changes made to this condition—the original “drug” condition from Study 2 of Lantian et al. (2024)—required to make the drug description minimally consistent with the “love drugs” concept/examples employed by Earp and Savulescu (2020a). Changes in bold.] After one month of treatment during which Paul had the feeling of a gradual increase of his love for Sophie, he feels again, as in the early days, love for his partner with whom he decides to stay	Paul is 30 years old and is in a relationship with Sophie for about ten years. Regrettably, he realizes that he no longer loves Sophie as much as in the early days of their relationship. He hesitates to stay in a relationship with her. Paul then goes to a doctor who recommends that he chooses one among several treatments. After having obtained Sophie ’ s consent, Paul chooses to take a revolutionary new treatment, under a pill form, that could improve his romantic condition by facilitating his appreciation of Sophie ’ s qualities. This revolutionary pill has been clinically tested and proven fairly reliable. However, like any intervention, it is not 100% effective. It doesn’t guarantee a successful result. Instead, it’s more of a "nudge"—a matter of probabilities. Basically, in combination with other factors—like the mindset and motivation of the person taking the pill—it can intensify the feeling of romantic love that we feel for a person. After one month of treatment during which Paul had the feeling of a gradual increase of his love for Sophie, he feels again, as in the early days, love for his partner with whom he decides to stay.	Paul and Sophie are 30 years old and have been in a relationship with each other for about ten years. They are married and have two young children. Regrettably, they realize that they no longer love each other as much as in the early days of their relationship. They hesitate to stay in a relationship with each other, and have even considered getting a divorce. But still, they think, there are reasons to try to make it work. For one thing, there are the kids to think about. And it ’ s not like they hate each other. Their values are basically in line. They have a lot in common: shared routines, shared finances, shared history. Their lives, their memories, and even their identities are intertwined. If they could only find a way to rekindle the flame between them! But so far nothing has worked. Not the couples retreat they went on. Not talk therapy. Not romantic vacations. One day, they read about a new study going on at a prestigious university in their town. The researchers are recruiting long-term romantic partners for a study on "pharmacologically-assisted psychotherapy for couples." According to the recruitment materials, the study involves taking a low-risk, non-addictive pill as a supplement to couples counseling. Like any intervention, this pill is not 100% effective. It doesn’t guarantee a successful result. Instead, it temporarily fosters greater feelings of empathy and connectedness between partners and enables people to talk more openly and honestly about their emotions and difficulties. However, once the immediate effects of the pill wear off—usually after a few hours—the couple still has a lot of work to do to apply whatever they’ve learned from the experience to their daily lives. Paul and Sophie decide to enroll in the study. The study lasts for one month, during which the couple undergoes two separate pill-enhanced therapy sessions, spaced out by a couple of weeks. As they work through their problems and learn to see each other again with "fresh eyes," Paul and Sophie feel a gradual increase in their love for one another. After one month of treatment, each of them feels again, as in the early days, love for each other and they decide to stay together.

The text in bold reflects different descriptions of how the pill works and its reliability between conditions. LantianS2 precisely replicates the text from the drug condition of Study 2 from Lantian et al. (2024) and is the least realistic of the 3 vignettes. LantianRealistic is the same text with the minimal required changes for the “love drug” to be consistent with the more ecologically valid concept and examples employed in our work (e.g., the drug is not “100%” reliable). And IdealCase is loosely adapted from a scenario in Earp and Savulescu (2020a, ch. 5) which is described as the “strongest contender” for the most realistic and morally justified use of love drugs. It thus differs significantly from the other two conditions, both by including details of the situation and motivations of the couple (e.g., they have children) and making explicit that the “pill” is meant to be used as an adjunct to couples therapy. Consequently, the vignette is also substantially longer than the other two; this should be kept in mind as a limitation and addressed by better matching of vignette lengths (i.e., word counts) in future studies.