People who need people: Trait loneliness influences positive affect as a function of interpersonal context

Trait loneliness is associated with negative health consequences; understanding involved processes may elucidate its contributory role. Evolutionary and reaffiliative models associate loneliness with negative affect and dysregulated cortisol responding, while the social monitoring system model associates loneliness with heightened salience of social cues. We hypothesized that loneliness would be associated with greater negative affect and cortisol reactivity, comparing a negative-evaluative audience Trier Social Stress Test ("audience condition;" n = 55) versus a no-audience control condition (n = 69) in non-depressed young adults. Opposing hypotheses, multilevel growth curve models indicated that loneliness was not associated with negative affect or cortisol reactivity in the audience versus no-audience condition. Loneliness was, however, associated with greater positive affect reactivity in the audience versus no-audience condition. In particular, the positive affect subfacet "Interest" was heightened in the audience condition but blunted in the no-audience condition as a function of loneliness, echoing a social monitoring system model of loneliness.