Summary for Study 2

Study 2 examined the extent to which FFM personality traits and the proxy psychopathy measure, the PSPT scale, could predict alcohol use as well as aggression in adolescence and

78 to compare the effectiveness of the FFM traits and PSPT scale in predicting these outcomes with a validated measure of psychopathy, the Youth Psychopathy Inventory. This was done because, at present, the validity of the PSPT scale still needs to be explored to see how useful the scale is in comparison to the standard FFM personality traits in predicting psychopathy-related outcomes.

If the PSPT factors are similar to the YPI higher-order factors, then the respective factors should show moderate to strong correlations. This is not to say that if two constructs correlate it follows that they measure exactly the same construct (i.e. Conscientiousness is correlated with psychopathy but in itself is does not index psychopathy). However, it would indicate a relationship between the two and is a good starting point for comparing the PSPT and YPI. In this sample, the PSPT secondary scale was correlated with the YPI Lifestyle factor, both of which are thought to index secondary psychopathic traits. However, the effect size for this relationship was small (r=.26). Therefore, although the Lifestyle factor and the PSPT secondary factor seem to be linked to some extent, it is possible that these two psychopathy factors do not measure the same construct, especially given the small correlation coefficient. For instance, the PSPT secondary factor includes items of N which measure emotional

reactivity. This aspect is not part of the YPI Lifestyle factor. Here the focus is put on impulsivity, irresponsibility and thrill-seeking.

The PSPT primary factor was not correlated with either of the YPI factors that index primary psychopathic traits. This was surprising as it was hypothesised that the primary PSPT factor would be associated with at least one of the YPI factors. Of the PSPT primary items half of the items measure anxiety, or rather the absence of anxiety (N). However, only one item taps into callousness and grandiosity. The YPI Interpersonal and CU factors assess the latter

79 two aspects but do not measure fearlessness or low anxiety. Their primary focus is

meanness (i.e. lack of empathy). This could explain why the relationship between the YPI factors and the primary PSPT factor is weak.

One of the difficulties in researching psychopathy is that assessments of the construct differ between measures, mainly because there are different perspectives within the literature regarding the factors constituting psychopathy. Some of these perspectives have already been touched upon in Chapter 1 (section 1.2) regarding a three or four factor structure including an interpersonal factor (e.g. superficial charm), a callous/unemotional factor (e.g. lack of guilt), a lifestyle factor (e.g. irresponsible) and an antisocial factor (e.g. deviant behaviour). However, another way to conceptualise psychopathy that helps to demonstrate the differences in psychopathy measures is through Patrick’s triarchic conceptualisation of psychopathy (Patrick, Fowles, & Krueger, 2009), which suggests three factors. The first factor, Disinhibition is similar to the Lifestyle factor and includes impulsive and reckless behaviour. The second factor, Meanness, includes lack of empathy and overlaps with the

Callous/Unemotional factor. The last factor is Boldness. Boldness describes characteristics

such as social dominance, low stress-reactivity and thrill-seeking and it is this last factor that is not focused upon as intensely within some of the most used psychopathy measures such as the Psychopathic Checklist-Revised (PCL-R: Hare et al., 1991). The PSPT scales on the other hand does include items measuring Boldness (e.g. “When I'm under a great deal of stress, sometimes I feel like I'm going to pieces.”(r); “I often feel inferior to others.” (r)). However, the PSPT does not focus as much on the Meanness component as do the PCL-R or the YPI. This limits the range of traits the PSPT scales can measure and ultimately limits their ability in capturing the entirety of the psychopathy construct. It would therefore be

80 would change the scales’ capability of measuring psychopathic traits compared to other validated psychopathy measures.

3.4.3.1. Aggression

Aggressive behaviour is both actively and indirectly destructive to other individuals and society as a whole. Psychopathy and related personality traits have been found to be good predictors of aggression with research suggesting the existence of different associations for proactive and reactive aggressive behaviour (Lynam, 1997). In line with previous research the findings of the current study suggest a strong association between psychopathic traits and aggression as well as low A and aggression.

Specifically, all YPI higher-order factors were predictive of reactive aggression, with the strongest association found for the YPI Lifestyle factor (secondary psychopathy). It is thought that this link exists because individuals with secondary psychopathic traits are typically more emotionally unstable than individuals with primary psychopathic traits (Hicks et al., 2004). They have increased levels of anger, hostility and impulsivity which, in turn, are linked to heightened levels of reactive aggression (Lawrence, 2006).

Primary psychopathic traits are often found to be strongly related to proactive aggression and reactive aggression and as indicated in this study, amongst the psychopathy-related factors of the YPI and PSPT, the YPI CU factor was the only predictor of proactive aggression. In this sample the YPI CU and Interpersonal factors were also predictive of reactive

aggression which is in line with the general finding showing a link between psychopathy and aggression (Borroni et al., 2014; Lynam, 2010). However, Kimonis and colleagues (2011) found that in an offender sample, primary psychopathic traits were more strongly related to proactive aggression and secondary psychopathic traits were more strongly related with

81 reactive aggression. Perhaps such distinctions are possible in forensic samples and are less likely to be observed in relatively young, community samples. Also, the link between

psychopathic-like traits and the different types of aggression may become more pronounced later in development within the normal population.

The findings for the FFM personality traits show important links with aggression. Proactive aggression was related to low C, low A, average levels of N and low E. Reactive aggression on the other hand was associated with a profile of high N, low C, low A and low E. These profiles correspond to primary and secondary psychopathy respectively, with N being the

distinguishing factor. This was also demonstrated here whereby individuals scoring high on the Lifestyle factor also had higher levels of N whereas this relationship was not found for the CU and Interpersonal factors.

In comparison, the PSPT scales were not able to make a distinction between proactive and reactive aggression because the PSPT primary traits were found to be unrelated to both types of aggression and only the PSPT secondary factor showed a correlation with the proactive and reactive aggressive behaviour. These findings suggest that the PSPT scales are not as sensitive as the standard FFM personality traits in distinguishing aggressive

psychopathy-related behaviour. It is therefore possible that using the standard FFM traits in relation to psychopathy-related outcomes is more meaningful than using the PSPT scales. A comparison of the regression models (i.e. adjusted R2) that examined the YPI higher-order factors, FFM personality traits and PSPT factors in predicting aggression demonstrated that the YPI factors showed the strongest link to aggression, followed by the FFM traits, with the PSPT scales showing the weakest associations. This suggests that personality traits based on the FFM contribute somewhat to the variance in explaining aggression, more than the PSPT

82 scales. However, psychopathic traits, as measured by the YPI, were most effective in

predicting aggression.

It is possible that FFM traits or the PSPT add incremental predictive value above and beyond the YPI factors. This was tested and the findings showed that the secondary PSPT scale does in fact add predictive value above and beyond the YPI for reactive aggression. This suggests that the secondary PSPT scale measures aspects relevant to psychopathy-related outcomes that are not addressed by the YPI. However, the primary PSPT scale only showed a weak association with reactive aggression and no association with proactive aggression which may indicate issues in accurately indexing primary psychopathic traits.

The findings of this study further indicated that none of the FFM traits added predictive value above and beyond the YPI factors for reactive aggression. However, low E was found to explain additional variance in proactive aggression over and above the YPI. This is

surprising given that there is only a small amount of research indicating a link between E and aggression. For instance, Pease & Lewis (2015) showed an inverse relationship between anger and E. Introverts seem to be less likely to be involved in stimulating interpersonal exchanges and therefore are less likely to be in situations involving reactive aggression, and may find emotional aggression overly stimulating. However, they may still be goal driven – and so may use aggression as a means to achieve aims.

In summary, aggression was best predicted by the psychopathy measure, the YPI. This was true for both types of aggression. The PSPT secondary scale added some incremental value in addition to the YPI in the prediction of reactive aggression, whereas the primary scale did not. Of the FFM traits, E added predictive value to explaining proactive aggression in

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3.4.3.2. Alcohol

Alcohol misuse can have severe consequences and is linked to psychopathy, in particular to secondary psychopathic traits (Kimonis, Tatar, et al., 2012; Neumann & Hare, 2008). It was therefore hypothesised that secondary psychopathic traits, measured by both the PSPT scale as well as the YPI, would show associations with alcohol use in this sample of adolescents. However, the YPI higher-order factors, Interpersonal, Callous/Unemotional and Lifestyle, as well as the two PSPT factors were not found to be related to alcohol use.

There was, however, one FFM personality factor, A, that predicted alcohol consumption, as was found in Study 2. Less agreeable individuals were more likely to have consumed alcohol by age 14. This is in line with previous research showing a consistent link between alcohol use and low A in adolescence (Kuntsche et al., 2006; Loukas et al., 2000; Markey et al., 2003). It was expected that C would also be related to alcohol use (Loukas et al., 2000; Markey et al., 2003). However, such a link was not found here.

3.4.3.3. Limitations of Study 2

There were a few constraints in this study that could have affected the results. The number of adolescents who, according to self-report, had never consumed alcohol was very high (66%). This means that the data had to be categorised into groups of adolescents who had never drank and those who had, thus reducing the power of the analysis (Altman & Royston, 2006). Under some circumstances it can still be meaningful to split the data into groups of abstainers and alcohol drinkers. White and Hingson (2013) found that the risk of alcohol dependence was higher for those adolescents who started drinking earlier in development. Therefore looking at those individuals in this sample who had already tried alcohol

84 low A played an important role in distinguishing those individuals who drank from those who did not at age 14. However, the findings from Study 1 were not entirely replicated, namely that high E and O as well as low C were also related to alcohol use. It could be that the same associations were not found in Study 2 because the sample was considerably smaller here. However, due to the considerable difficulties in recruiting the current sample as well as time constraints of this research, it was not possible to recruit a larger sample.

Next, the PSPT primary scale was not related to proactive aggression as was expected. It is noteworthy that within the normal population scores for aggression and particularly proactive aggression are never expected to be very high. Therefore examination of such behaviour is difficult not only because of social desirability bias issues but also because of potential restricted variability within the data.

In addition, a larger sample would inevitably increase financial costs because the NEO-FFI is purchased at a reasonably high price. Consequently, in order to investigate personality traits, especially in larger research projects, it would be more efficient to use freely available

personality measures, such as the International Personality Item Pool (IPIP).

Finally, it is not clear how these findings translate to individuals in later adolescence or early adulthood. Mechanisms that are linked to problem behaviours such as excessive alcohol use or aggression change over time. Tucker and colleagues showed that binge drinking

behaviour changed from age 13 to 23 with different clusters of individuals displaying different trajectories; e.g. a cluster of high binge drinkers in early adolescence decreased binge drinking behaviour over time or a cluster of individuals steadily increasing binge drinking behaviour from age 13 to 23 (Tucker, Orlando, & Ellickson, 2003). Additionally, in this study primary psychopathic traits were expected to be related to proactive aggression.

85 However this was not found. Perhaps this was due to the sample being a young community sample where the link between psychopathic traits and proactive aggression may not have been strong enough to be detected. Therefore in the next study we investigated whether psychopathic traits are predictive of risk-taking behaviours, i.e. alcohol use and aggression, in young adults (age range 17-21 years).