Self- and peer-reported personality: Agreement, trait ratability, and the "self-based heuristic"

Agreement between self- and peer-reported personality was investigated using the Schedule for Nonadaptive and Adaptive Personality (SNAP; Clark, 1993) and SNAP-Collateral-Report Version. Participants were 189 well-acquainted undergraduate pairs (64% female; 83.2% Caucasian; age M = 19.7 years) of either same (n = 129) or mixed gender (n = 60). Self-peer agreement correlations averaged .47 (range, .27-.62). Agreement variation across traits was associated with ratability (r = .58): Traits whose component items were judged more difficult to rate were associated with lower agreement. The degree to which the raters' own personality contributed to target ratings also was correlated negatively with agreement (r = -.60) and exhibited a strong relationship with ratability (r = -.73). Thus, when peers were asked to rate a target on difficult-to-judge traits, they reported more on their own personality, a phenomenon to which we apply the interpretive label the "self-based heuristic." (C) 2000 Academic Press.