Acquaintanceship length as a moderator of self-informant agreement in life-satisfaction ratings

Meta-analyses have shown moderate agreement between self-ratings and informant ratings of personality and well-being. The influence of acquaintanceship length on self-informant agreement in life-satisfaction judgments was examined using 922 participants from friendship and relationship dyads. Data were analyzed using non-linear mixed models to estimate the shape of the acquaintanceship effect and to account for the dependence of dyadic data. Results revealed a significant, non-linear acquaintanceship effect, indicating that self-informant agreement increases over the first 3 years of a relationship to within 90% of the maximum level of agreement. The maximum agreement was estimated to be r = .34, which is consistent with meta-analytic findings of self-informant agreement in life-satisfaction judgments for well-acquainted informants.