Positivity resonance predicts lasting love, according to new psychology research

An analysis of data from 148 long-term married couples suggests that couples who display greater positivity resonance tend to score higher on a measure of enduring love. Moment-to-moment fluctuations in positivity resonance were also associated with changes in love over time. The research was published in Personal Relationships.

Positivity resonance refers to the shared experience of positive emotion between two (or more) individuals. It arises when people connect in a way that fosters warmth, trust, and a sense of shared humanity. This state is marked by nonverbal synchrony, such as matching facial expressions, coordinated body language, and harmonized tone of voice.

It can occur during everyday interactions—such as shared laughter, mutual eye contact, or a heartfelt conversation—and is thought to trigger the release of neurochemicals like oxytocin, which help reinforce social bonds. Over time, frequent experiences of positivity resonance may support emotional well-being and even physical health. Although often studied in romantic contexts, positivity resonance can occur in friendships, family interactions, and even brief encounters with strangers.

Study author Jocelyn Lai and her colleagues aimed to test whether positivity resonance between romantic partners is associated with markers of love. Specifically, they sought to determine whether couples who experience more frequent positivity resonance also report—or display—more love. The researchers also hypothesized that changes in positivity resonance over time would be linked to changes in momentary expressions of love.

The authors analyzed data from a longitudinal study of marital satisfaction and relationship quality. Participants were 148 middle-aged and older heterosexual couples recruited from the San Francisco Bay Area between 1989 and 1990. On average, husbands were 54 years old and wives were between 52 and 53. The couples had been married for an average of 30 years.

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In the original study, couples visited a laboratory and engaged in a 15-minute conversation about a marital conflict. This occurred during two sessions spaced over time. Approximately 1.5 years after the first visit, they completed a questionnaire in which they selected adjectives that described their spouse. During the conversations, participants were video recorded and wore electrocardiography equipment to monitor their heart activity.

The researchers analyzed these videos to assess each couple’s level of positivity resonance. They focused on jointly experienced and expressed positive affect, physiological linkage in heart rate, and behavioral cues such as tone of voice and facial expressions. State love was estimated from nonverbal cues displayed in synchrony during short segments of the conversations. Trait love—a more stable form—was estimated using both the love-related adjective ratings and the overall frequency of synchronized nonverbal cues during the conversations.

The results indicated that couples who exhibited higher levels of positivity resonance tended to show greater trait love. In other words, couples who shared more positive emotional synchrony were also estimated to love each other more in a stable, enduring sense. Additionally, moments of increased positivity resonance within the conversations were associated with higher levels of state love, and vice versa.

“Results offer the first empirical footing for the theoretical claim that positivity resonance reflects state love and predicts trait love. As researchers continue to advance empirical work on positivity resonance, they now have a basis for presenting that evidence as also advancing the science of love,” the study authors concluded.

The study contributes to the scientific understanding of the relationship between love and positivity resonance. However, it should be noted that the same videos were used to estimate both love and positivity resonance, raising the question of whether they can be considered independent observations. It is possible that at least a part of the reported association stems from the fact that estimates of love and positivity resonance came from the same videos.

The paper, “Does Positivity Resonance Signify Love? Markers of Positivity Resonance in Long-Term Married Couples Relate to Trait and State Love,” was authored by Jocelyn Lai, Marcela C. Otero, Kuan-Hua Chen, Jenna L. Wells, Robert W. Levenson, and Barbara L. Fredrickson.