Personality in New Zealand: Scale Norms and Demographic Differences in the Mini-IPIP6

There have been many studies examining how various isolated demographic factors predict various specific aspects of personality (Goldberg, Sweeney, Merenda, & Hughes, 1998). These studies generally seek to answer questions about differences in some specific personality trait, such as: do men and women differ in their level of Extraversion? Do older and younger people differ in their level Narcissism? Does poverty predict lower levels of emotional stability or conversely, higher levels of personality vulnerability (as indexed by Neuroticism)? Research examining personality differences in the New Zealand population is sparse and fairly fragmented, however (see Cox, 2008; Guenole, & Chernyshenko, 2005; Packman, Brown, Englert, Sisarich, & Bauer, 2005; Roberts, Caspi, & Moffitt, 2001; Wilson & Sibley, 2011). McCrae et al. (2005), for example, compared the personality scores of undergraduate students from 51 cultures and reported that, generally speaking, New Zealand undergraduates were among the most extraverted; and of the cultures examined, the most similar to Australian, North American, English and Irish undergraduates. However, we know little about demographic differences in personality in the New Zealand population more generally--outside of the study of undergraduates. What then does the personality of New Zealanders look like? Extant research, both the small amount conducted in New Zealand, and much of that conducted overseas, has focused on small isolated sets of demographic factors and a select few personality traits using non-representative samples. This is problematic because such analyses do not take into account possible overlap with other demographic factors (young adults and older adults may, for example, earn less than middle ages adults, and income might hence contribute to the apparent age effect). In addition, many of these differences may be culturally specific, or at least the size of the relative effects might be shaped by national-level factors. For example, men tend to be more socially dominant than women on average, but the size of this gender difference depends upon the level of gender inequality in society (Lee, Pratto, & Johnson, 2011). This example highlights the risks of generalizing demographic differences in personality across nations. In this paper we present a comprehensive analysis of demographic differences in the Big-Six factors of personality in the New Zealand population using the Mini-IPIP6 (Sibley et al., 2011). The Mini-IPIP6 is a public domain short-form personality instrument based on the original five-factor Mini-IPIP presented by Donnellan, Frederick, Oswald, and Lucas (2006) derived in turn from the broader item pool developed by Goldberg (1999). The Mini-IPIP6 provides four-item markers of six broad-bandwidth dimensions of personality: Extraversion, Agreeableness, Conscientiousness, Neuroticism, Openness to Experience and Honesty-Humility. Definitions and example traits for each of these six personality dimensions are presented in Table 1 (see also Sibley et al., 2011, for further details). Table 1 further outlines the proposed evolutionary costs and benefits of high and low levels of each trait. As far as we are aware this study constitutes the most comprehensive, representative, and extensive analysis of demographic differences and the distribution of personality traits in the New Zealand population conducted to date. Here we analyse Mini-IPIP6 scores from the first wave of the New Zealand Attitudes and Values Study (NZAVS). This is a nationally representative longitudinal study of around 6000 New Zealanders collected in 2009. This study answers a swathe of questions about differences and similarities in the personality of New Zealanders about which we have had only tentative data based on relatively small and largely non-representative samples. The study thus aims to provide comprehensive baseline information about the distribution of personality in the New Zealand population and resolve debate about differences and similarities in personality across demographics. …