Development is in the details: Age differences in the Big Five domains, facets, and nuances.

Abstract

We examined the extent to which the Big Five domains, 30 facets and nuances (uniquely represented by individual questionnaire items) capture age differences in personality, expecting domains to contain the least and nuances the most age-related information. We used an Internet sample (N = 24,000), evenly distributed between ages of 18 and 50 years and tested with a 300-item questionnaire. Separately based on domains, facets and items, we trained models to predict age in one part of the sample and tested their predictive accuracy in another part. Big Five domains predicted age with an accuracy of r = .28, whereas facets' (r = .44) and items' (r = .65) predictions were more accurate. Less than 15% of the sample was needed to train models to their optimal accuracy. Residualizing the 300 items for all facets had no impact on their predictive accuracy, suggesting that age differences in specific behaviors, thoughts and feelings (i.e., items) were not due to domains and facets but mostly unique to nuances. These findings replicated in a multi-sample dataset tested with another questionnaire. We found little evidence that age differences only appeared nuanced because items referred to age-graded roles or experiences. Therefore, a substantial part of personality development may be uniquely ascribed to narrow personality characteristics, suggesting the possibility for a many-dimensional representation of personality development. Besides theoretical implications, we provide concrete illustrations of how this can open new research avenues by enabling to study systematic variations between traits.

Traits and Adaptations: A Theoretical Examination and New Empirical Evidence

“…For example, it may be that more BT‐like constructs have different developmental causes and trajectories than more CA‐like constructs. Lumping BT‐like and CA‐like nuances (items) into broad aggregates such as the Big Five may explain why they have been hard to reliably link with specific genetic variants (Lo et al, 2017) or life experiences (Denissen et al, 2019), or why these broad aggregates filter out a substantial part of the otherwise measurable age differences in personality (Mõttus & Rozgonjuk, in press). Also, it may be that BT‐like and CA‐like nuances differ in how they are linked with life outcomes in general or with specific types of outcomes; for example, it may be that specific adaptations drive associations with narrow, circumscribed outcomes, while BTs drive associations with broad life outcomes that draw on many trait domains over extended periods of time.…”

“…Moreover, recent findings show that hundreds of questionnaire items contain unique variance with properties typically associated with traits. These include (i) stability over more than a dozen years, (ii) agreement across assessment methods, and (iii) heritability (Mõttus, Kandler, Bleidorn, Riemann, & McCrae, 2017; Mõttus et al, 2019), as well as (iv) distinct developmental patterns (Mõttus & Rozgonjuk, in press) and (v) predictive validity (Seeboth & Mõttus, 2018). This has led some theorists to suggest that items represent both traits and adaptations at the same time (Costa & McCrae, 2017).…”

“…The trait hierarchy can be extended even below facets. Recent research suggests that specific behavioural, cognitive, and affective patterns operationalized with individual questionnaire items such as ‘I enjoy parties’ or ‘I leave my belongings around’ also display stability and cross‐method agreement, and most of them also show distinct aetiology in terms of heritable variance and disparate developmental patterns (Mõttus, McCrae, Allik, & Realo, 2014; Mõttus et al, 2015; Mõttus et al, 2017; Mõttus & Rozgonjuk, in press). This applies even when variance due to higher order traits (e.g.…”

“…facets or domains) for which item content and verbal label/summary may not entirely match. Also, items are numerous, providing more statistical power to study systematic quantitative variability among them (Mõttus & Rozgonjuk, in press). Indeed, as far as CB5T is concerned, questionnaire items can independently measure either traits or CAs: some items focus ‘on a particular adaptation, in all its cultural and personal specificity, whereas others “simply describe culturally universal traits”’ (DeYoung, 2015, p. 41).…”

“…Because of complexities associated with interpreting items' unique variance (after having been residualized for facets and domains, as has been done before for other purposes; e.g. Seeboth & Mõttus, 2018; Mõttus et al, 2017, 2019; Mõttus & Rozgonjuk, in press) in this context, we ultimately chose not to correlate items' BT‐ness and CA‐ness ratings with the stability, cross‐rater agreement, and heritability of their unique variance. If all theories proposed a unidirectional relationship from traits to CAs, we could consider items' residual variance a result of more specific traits, independent of higher order factors, besides CAs (for an informative overview of parsing item variance, see McCrae, 2015).…”