Martijn van Teffelen

Chapter 3 58 in the possibility that (for example) there is a relationship between provoked aggression and psychopathic/narcissistic traits. Then, we collect data and adjust this prior degree of belief to the posterior degree of belief. A Bayes factor (BF 10 ) is an index for the degree that the prior belief is re-allocated to the posterior belief (Kruschke & Liddell, 2018). Bayes’ factors were interpreted using interpretation categories (i.e., to determine the strength of a Bayes’ factor) according to Jeffreys (1961). 1 Third, relationships between the outcome variables (i.e., unprovoked aggression, provoked aggression, change in negative affect, and threat perception) and the independent variables (i.e., psychopathic, and narcissistic traits) were explored. Pearson’s correlation analysis was applied to test the bivariate relationships between unprovoked and provoked aggression, change in negative affect, threat perception, psychopathic traits, and narcissistic traits. Multiple linear regression analysis was run to explore the unique predictive value of independent variables psychopathic and narcissistic traits (i.e., residualized) on dependent variables unprovoked and provoked aggression, change in negative affect, and threat perception. All predictors were simultaneously entered in the model. Last, (moderated)-mediation models were tested using the PROCESS Macro version 3.4 for SPSS (Hayes, 2013). In the psychopathy mediation model psychopathic traits were entered as independent variable, change in negative affect as mediator variable and provoked aggression as independent variable. In the narcissismmoderated-mediation model narcissistic traits were entered as independent variable, perceived threat as mediator, condition as moderator (between narcissistic traits and perceived threat) and unprovoked aggression as dependent variable. RESULTS For means and standard deviations of study variables, see Table 2. All variables were normally distributed, except for the positively skewed negative affect indices (i.e., the value 0 is outside the +/- 2 * standard error interval of the skewness value). Psychopathic and narcissistic trait scores resembled those of other studies using non-clinical male samples (Lobbestael et al., 2014; Uzieblo et al., 2010). Table 2 shows that there were no group differences at baseline regarding psychopathy, narcissism, and NA scores, indicating successful random group allocation. 1 Bayes’ Factor (BF 10 ) categories, where H 1 = the alternative hypothesis and H 0 = the null hypothesis are as follows. BF 10 > 100: extreme evidence for H 1 . BF 10 = 30-100: very strong evidence for H 1 . BF 10 = 10 – 30: strong evidence for H 1 . BF10 = 3 – 10: moderate evidence for H 1 . BF 10 = 1 – 3: anecdotal evidence for H 1 . BF 10 = 1: no evidence. BF 10 > 1/3 – 1 anecdotal evidence for H 0 . BF 10 = 1/3- 1/10: moderate evidence for H 0 . BF 10 = 1/10 – 1/30: strong evidence for H 0 . BF 10 = 1/30 – 1/100: very strong evidence for H 0 . BF 10 < 1/100: extreme evidence for H 0 .