Trait ascription bias

Jones and Nisbett[7] were among the first to argue that people are biased in how they tend to ascribe traits and dispositions to others that they would not ascribe to themselves. Motivated by the classic example of the student explaining poor performance to a supervisor (in which the supervisor might superficially believe the student's explanations but really thinks the performance is due to "enduring qualities": lack of ability, laziness, ineptitude, etc.) their actor–observer asymmetry argument forms the basis of discourse[1][8][11] on trait ascription bias.

In a 1982 study involving fifty-six undergraduate psychology students from the University of Bielefeld, Kammer et al. demonstrated that subjects rated their own variability on each of 20 trait terms to be considerably higher than their peers.[1] Building on the earlier work of Jones and Nisbett,[7] which suggests people describe the behaviour of others in terms of fixed dispositions while viewing their own behaviour as the dynamic product of complex situational factors, Kammer hypothesized that one's own behaviours are judged to be less consistent (i.e. not as predictable) but of higher intensities (with regard to particular traits) than the behaviour of others. The experiment had each student describe themselves as well as a same-sex friend using two identical lists of trait-descriptive terms. For example, for the trait of dominance the student was first asked "In general, how dominant are you?" and then "How much do you vary from one situation to another in how dominant you are?"[1] Kammer's results strongly supported his hypothesis.

David C. Funder's work[8] on the "trait" of ascribing personality traits investigates the psychology of individuals who tend not to grant others the variability (i.e. lack of predictability) they grant themselves, instead preferring to ascribe traits and infer dispositional explanations of behaviour. It had been generally established[7] that people ascribe more traits to others than to themselves, known as the actor–observer asymmetry in attribution,[7] but Funder's hypothesis was that some individuals are more inclined to make dispositional trait attributions than others, regardless of who they are describing.[8] In the experiment, sixty-three undergraduates filled out a series of questionnaires which asked them to describe themselves, their best friend, and an acquaintance. For each of twenty pairs of polar opposite trait terms (e.g. "friendly—unfriendly") subjects either ranked the person on a discrete scale or chose "depends on the situation", allowing the subject to "not make a dispositional ascription."[8] Based on third-party Q-Sort personality descriptions of the subjects, certain negative personality traits were correlated with those subjects who tended to ascribe dispositions to others, while traits such as "charming", "interesting", and "sympathetic" were associated[12] with those who preferred not to ascribe traits. This result is consistent with the type of personality commonly associated with promoting stereotypes and prejudice.

Tversky and Kahneman describe a cognitive heuristic that suggests people make judgments (including about other people's personalities[14]) on the basis of how easily examples of their (other people's) behaviour come to mind.[15][16] This would appear to be consistent with the arguments of Jones and Nisbett[7] and the results observed by others[1][8] which found that people ascribe fewer traits to friends than to acquaintances, and fewer still traits to themselves than to friends, implying ease of recall might be a factor.

Attribution plays a role in how people understand and judge the causes of the behaviour of others,[2] which in turn affects how they ascribe traits to others. Attributional theory[17] is concerned with how people subsequently judge behavioural causes, which also bears relevance to trait ascription and related biases. In particular, attribution (and attributional) theory can help explain the mechanism by which individuals defer to ascribing dispositional traits vs. situational variability to observers.[18]

The big five personality traits (or five factor model) arguably[4][13] provides a robust set of traits by which personalities can be accurately described. It supports the notion that there are cross-cultural, enduring traits which manifest in behaviour and can, if correctly ascribed to individuals, provide an actor with predictive power over an observer.