Moody and thin-skinned? The interplay of neuroticism and momentary affect in older romantic couples

Neuroticism is associated with heightened reactivity to social stressors. However, little is known about the micro-processes through which neuroticism shapes - and is shaped by - affective experiences in close relationships. We examine the extent to which momentary affect is coupled with one's relationship partner, whether the strength of this coupling differs depending on levels of neuroticism, and whether this coupling and partner's overall level of positive or negative affect prospectively contribute to differential (rank-order) changes in neuroticism. Older couples (N = 82, aged 67-93 years) rated their momentary affect six times per day for one week and provided ratings of trait neuroticism at baseline and 18 months later. Multilevel models revealed that among individuals high in neuroticism, individual positive affect was more closely coupled with partner positive affect compared with individuals low in neuroticism. Moreover, neuroticism decreased over time in those participants who showed a higher degree of coupling with partner positive affect and also had a partner with higher overall positive affect. In contrast, neuroticism increased in individuals whose partner had lower overall positive affect. Similar effects were not observed for negative affect. Our findings highlight how relationship partners contribute to daily affective experiences and longer-term changes in neuroticism.