A while ago, we asked you all to to participate in actual research. A lot of you did, and now the results are in.

Consensual non-monogamy (CNM) - where couples decide not to be sexually exclusive with one another - is becoming increasingly popular. What is the impact of opening up? Does it ruin your relationship? Is it a panacea for marital problems? Without longitudinal data, we can’t know.

@annelise_murphy has collected the first prospective, longitudinal data on the decision to practice CNM. She recruited people who were interested in opening their relationships but who hadn’t taken the plunge yet and tracked them as they did or did not open up over two months.

We wound up with 155 openers: people who opened their relationships between Times 1 and 2. We also had 78 non-openers: people were still monogamous by Time 2. The design allowed us to compare openers to the non-openers, as well as changes over time for each group.

We preregistered the study design, including stopping rules. We had some confirmatory hypotheses about motives, but none about the main effects of opening up. Honestly, we had no idea how these results would turn out.

We found that by Time 2, openers had significantly higher relationship quality and sexual satisfaction compared to the non-openers. BUT: those differences were already present at Time 1. Relationship quality did not change over time as people opened up their relationships.

Put differently: People who opened up their relationships to other partners did not enjoy better relationships as a consequence of CNM. Instead, the people who opened up their relationships had higher relationship quality to begin with.

Sexual satisfaction, on the other hand, actually did increase over time for the openers. People who opened up their relationships enjoyed boosts in relationship satisfaction from Time 1 to Time 2. In contrast, the non-openers did not.

Why did opening up lead to higher sexual satisfaction? It could be as straightforward as the fact that new sexual partners are novel and exciting. It could also be that CNM helps couples communicate better about their sex lives.

The work has some limitations. First, we did not collect partner reports, so we don’t know how our participants’ partners felt about the decision to practice CNM, or what the consequences of that decision might have been for them.

We also recruited a sample of people who were already enthusiastic about CNM, by definition. It seems unlikely that these results would extend to people who hold negative attitudes about CNM.

On the whole, these results offer cautious optimism for people who are thinking about practicing CNM. We found some positive consequences of opening up and no negative ones. These findings support the idea that CNM can be a healthy, viable relationship option