The Dark Triad beyond the SPI: Providing Incremental Validity in Predicting Prosocial and Risky Behaviours

Personality measures have been criticized for their lack of coverage of some traits. As a result, researchers have examined and combined measures to better understand and predict target behaviours. The Supernumerary Personality Inventory (SPI; Paunonen, 2002) was designed to measure a wide range of personality traits, including antisocial tendencies. The Dark Triad (Paulhus & Williams, 2002) was developed specifically to measure the socially malevolent traits of psychopathy, narcissism, and Machiavellianism. Previous studies revealed significant correlations between the SPI traits and the Dark Triad traits, which suggest that the two measures may share some of the same theoretical underpinnings. The present study investigated the Dark Triad’s incremental validity beyond the SPI in predicting both prosocial and risky behaviours. Participants were 118 university students (31 males, 87 females) who completed self-report measures of the SPI and the Dark Triad traits. Hierarchical linear regression analyses were conducted with the 10 SPI traits inputted in the first model, and the three Dark Triad traits inputted in the second model in order to predict a series of behavioural criteria. Results showed that the SPI significantly predicted risky behaviours, but not prosocial behaviours. It was also showed that the Dark Triad did not add incrementally to the SPI’s prediction of prosocial and risky behaviours. Dark Triad, SPI and Anti-Social Tendency 3 The Dark Triad beyond the SPI: Providing Incremental Validity in Predicting Prosocial and Risky Behaviours Researchers have developed measures to assess various personality constructs derived from theory, which can then be used in research and clinical practice to further inform our understanding of personality. Understanding the means by which behaviour change occurs, as well as the prediction of various behaviours, are some of the cornerstones of scientific psychology. Furthermore, the study of personality and individual differences plays a role in the understanding of human behaviour. Personality psychology has a long history dating back to the writings of Freud, and more current literature has identified personality as comprising both broad personality factors and narrower traits. The most widely accepted view of personality is reflected in the Five-Factor Model, which highlights five broad personality traits: Neuroticism, Extraversion, Openness to Experience, Agreeableness, and Conscientiousness (Digman, 1990; McCrae & Costa, 2011; McCrae & John, 1992). While there has been some suggestion that the overlap between these factors may define a general personality factor, most studies of the Five-Factor Model have shown promising results in predicting a large number of behaviours. Some researchers have looked within each of these major traits to further understand the ‘make-up’ of each. For example, extraversion would include such narrow traits as sociability and assertiveness (McCrae, Costa, & Martin, 2005). The Supernumerary Personality Inventory (SPI) represents this narrow trait personality perspective (Paunonen, 2002). The SPI assesses 10 traits that are covered by the broader Five-Factor Model, and is described in detail in a section to follow. More recently, researchers Dark Triad, SPI and Anti-Social Tendency 4 have focused attention on specific personality characteristics that have been extensively described in clinical psychology with a particular focus on personality disorders, psychopathology, and forensic psychology. There has been a recent in focus on these traits as “subclinical” traits that can emerge within the general population. The most widely examined group of these subclinical traits is labelled “The Dark Triad,” consisting of three socially malevolent constructs: Machiavellianism, narcissism, and psychopathy (Paulhus & Williams, 2002). Because of its focus, the Dark Triad has been used to assess and predict human antisocial tendencies. Both broad (e.g., the Five-Factor Model) and narrow (e.g., the SPI and the Dark Triad) personality measurements advance the knowledge about personality constructs and the prediction of behaviours. However, one of the major criticisms of all personality measures is the insufficient coverage of some traits. Of course, the question is more a function of personality theories and models, and therefore the actual measurement via questionnaires, observations, and interviews are necessarily limited by practical considerations; the same may be said for intelligence tests. For example, the Five-Factor model fails to encompass sufficient trait coverage in terms of socially malevolent constructs. Therefore, it demonstrated weak predictability of antisocial behaviours such as materialism and unethical behaviours (Hong, Koh, & Paunonen, 2012). Because it has been argued that a personality measure does not encompass the full range of personality traits, many studies have examined the incremental validity of one measurement over the other. For example, Paunonen and Ashton (2001) showed that the SPI, a narrower measure of personality, was able to substantially increase the prediction of health-risk behaviours that have been achieved by the Dark Triad, SPI and Anti-Social Tendency 5 broad Five-Factor Model (Hong & Paunonen, 2009). Again this is not dissimilar to the assessment of intelligence where one may use a Wechsler-type test but then add to that more specific measures of memory, processing speed and executive functioning. Thus, it is important to add or combine another personality scale to understand and predict targeting behaviours when one model is inadequate. The present study examines this particular issue by examining the Dark Triad’s incremental validity beyond the SPI in predicting behaviours that reflect socially negative actions The Supernumerary Personality Inventory (SPI) Paunonen (2002) identified 10 supernumerary traits that are beneath the Five-Factor model. The 10 traits in the SPI include conventionality (want to preserve existing traditions; are opposed to radical changes), seductiveness (intend to attract the romantic or sexual interests of others), manipulativeness (like to manipulate others to achieve a goal), thriftiness (try not to waste resources on self-gratification), integrity (inhibit stealing, cheating, or deceiving behaviours), femininity (be more feminine for his or her own sex), religiosity (believe in a higher power that controls human destiny), risk-taking (seek possible danger with excitement), and egotism (exaggerated sense of self-importance). Research has demonstrated that the SPI captures a wider range of personality traits partially because it covers antisocial traits that are not measured by the Five-Factor model (Hong et al., 2012). However, although the SPI questionnaire assesses antisocial tendencies such as Manipulativeness and Risk-Taking, it was not specifically designed to assess socially malevolent traits. Although research demonstrated that the SPI successfully predicted some socially malevolent traits such as materialism and unethical behaviours, further Dark Triad, SPI and Anti-Social Tendency 6 research on the SPI predicting other antisocial behaviours is needed. The Dark Triad of Personality The Dark Triad (Paulhus & Williams, 2002) specifically identifies three major antisocial traits. Machiavellianism refers to the tendency of manipulating others (e.g., “Make sure your plans benefit you, not others”). Individuals who scored high on this trait tended to believe that interpersonal manipulation is the key for life success (Jones & Paulhus, 2009). Narcissism refers to dominance and a sense of superiority towards the self (e.g., “People see me as a natural leader”). Psychopathy represents callous social attitudes, erratic lifestyle, and criminal tendencies (e.g., “Payback needs to be quick and nasty”). Moderate positive correlations have been found among the three variables, suggesting that the variables overlap to an extent, but are essentially distinct constructs that measure different traits. Some researchers were interested in the positive correlation among the three variables and suggested that the variables may share a common underlying element. The trait of disagreeableness may explain the correlation because it was found that the Dark Triad was only correlated with agreeableness measured by the Five-Factor Model (Jakobwitz & Egan, 2006). However, other alternative explanations exist and therefore more research is needed to understand the construct of the Dark Triad. The Dark Triad has been reported to predict socially malevolent behaviours. More specifically, it was found that psychopathy positively predicted health-risk behaviours such as tobacco and alcohol consumption that led to shorter life expectancy (Jonason, Baughman, Carter, & Parker, 2015). Machiavellianism was negatively correlated to altruism, the concern of others that is not motivated by self-interest (Stead & Fekken, 2014). Different types of aggression were Dark Triad, SPI and Anti-Social Tendency 7 predicted by psychopathy and narcissism (Henderson & Bobadilla, 2011). Psychopathic individuals were more likely to be identified as bullies (Baughman, Dearing, Giammarco, & Vernon, 2012), and to cheat in a classroom (Nathanson, Paulhus, & Williams, 2006). Finally, a behavioural genetic analysis indicated that the variance in the Dark Triad scores could be largely attributed to genes and non-shared environment (Veselka, Schermer, & Vernon, 2011). This result suggested that the dark traits may serve an evolutionary purpose by fostering reproductive success (Brumbach, 2007; Jonason, Li, Webster, & Schmitt, 2009).