Individuals learn to influence and manipulate others to function
as part of society. Machiavellianism captures one’s willingness
to orchestrate the behaviour of others against their interests,
rights, and well-being. Research focuses primarily on a single
Machiavellianism dimension. This thesis, however, contends that
Machiavellianism comprises two correlated dimensions: a views
dimension that captures one's cynical and distrusting view of
humanity and the world, and a tactics dimension that captures
one’s willingness to endorse exploitative and amoral behaviours
when deemed advantageous. This thesis aimed to develop a stronger
understanding of each dimension, and this required developing
stronger psychometric instruments. The secondary aim was to test
the presupposition of no psychopathological cost to
Machiavellianism.
After an initial foray into Machiavelli and Machiavellianism in
the first two chapters, Chapter 3 identifies a robust
Machiavellianism factor-structure and how each dimension relates
to psychopathological domains in 1478 US and 218 Australian
participants. Confirmatory factor analysis demonstrated that
Machiavellianism comprises two robust dimensions which could be
reliably captured through a 10-item subset of the Mach-IV scale,
named Two-Dimensional Mach-IV (TDM-IV). Further, Machiavellian
views associated with all major psychological domains, while
Machiavellian tactics related only to the externalising and
thought dysfunction domains. Machiavellianism is two-dimensional,
with each dimension having distinctive psychopathological
implications.
The study in Chapter 4 investigates whether these two dimensions
are universal, or merely measurement artefacts within Study 1. If
universal, this research further aimed to develop a nomological
network to better understand the nature of each dimension.
International collaborators shared 15 datasets, which
comprisedover 17,000 participants. The two-factor structure was
reproducible and structurally equivalent across cultures,
languages, types of respondent, response category length, age,
and gender. Further, each dimension was situated within a
different constellation of broad personality traits,
developmental pathways, emotionality, and behaviour. Therefore,
the two dimensions appear to be core aspects of Machiavellianism
and need to be independently captured in future research.
The TDM-IV derives from the Mach-IV, inheriting many of its
psychometric concerns that reduce the accuracy of its inferences,
such as confusing item wording and not accounting for acquiesces
appropriately. To overcome these weaknesses, Chapter 5 presents
the development and validation of the Two-Dimensional
Machiavellianism Scale (TDMS). The TDMS had excellent
psychometric properties in six independent samples involving over
3800 participants, based on confirmatory factor analysis,
longitudinal structural equation modelling, and item response
theory. The scale provided invariant measurement across all
samples and a test-retest sample, was internally consistent, and
provided most information in the low to high average range. This
study demonstrates confirmatory and discriminatory validity
with existing measures of Machiavellianism, broader personality
taxonomies, socio-political attitudes, psychopathy, narcissism,
and morality vignettes.
Finally, Chapter 6 explicates this two-dimensional
Machiavellianism construct and discusses key areas for future
investigation, including latent profiles, longitudinal modelling
of each dimension’s development, and cross-cultural
equivalence. Together, this research demonstrates that: a)
Machiavellianism comprises two distinct
dimensions, b) the TDMS, as a psychometrically robust measure of
Machiavellianism, should replace current measures of
Machiavellianism, and c) the presupposition of psychopathological
immunity among Machiavellians is false
