Beschreibung:
<jats:p> There is a notable similarity in psychological well-being among romantic partners. Drawing on valence asymmetry research (e.g., negativity bias), we tested whether partners’ convergence toward a similar level of well-being is marked by the happier partner’s over-time deterioration or by the less happy partner’s over-time improvement. In two studies using nationally representative samples of German and Dutch couples ( N<jats:sub>couples</jats:sub>=21,894) followed for 37 (Study 1) and 14 (Study 2) years, we compared romantic partners’ well-being trajectories. Over time and within each couple, the happier partner experienced the most dramatic well-being declines; the unhappier partner’s well-being either did not change or increased slightly. Across all model specifications, the decline experienced by the happier partner was significantly stronger than any improvement reported by the less happy partner. The results provide the first evidence for a “negativity bias” in well-being co-development in couples and contribute to literatures in developmental psychology and relationship science. </jats:p>