Australasian Science: Australia's authority on science since 1938

The Dark Side

By Tim Hannan

A new study suggests that dark personality traits are the expression of a single underlying disposition.

Both the course of human history and the events of everyday life provide many examples of the worst of human nature. These behaviours don’t seem to be diminishing in frequency given the prevalence of serial killer documentaries on Netflix, the findings of the Royal Commission into banking, and the off-season transgressions of rugby league players.

Explorations of the so-called “dark” aspects of humanity have often involved an attempt to identify specific personality traits that are common to those who engage in antisocial behaviour. While these traits have usually been examined independently, a recent study has argued that these and other dark personality traits have a single common underlying factor – the tendency to maximise one’s personal goals and interests over those of others.

Historically, theories of the nature and motivation of anti-social behaviour have employed psychological constructs such as psychopathy, which refers to antisocial behaviour accompanied by a lack of empathy or remorse; narcissism, which is defined as an excessive need for admiration, usually accompanied by a grossly inflated opinion of one’s own abilities; and Machiavellianism, which labels a tendency to deceive and manipulate others for personal gain.

While each of these may occur in isolation, research has suggested that they often co-occur. Together, these three traits are said to comprise the “dark triad” of personality traits, the presence of which is believed to predict an increased likelihood of committing crimes, or of causing significant distress to others in organisations, communities or personal relationships. Some psychologists have extended this to a “dark tetrad”, which includes everyday sadism, defined as the enjoyment of cruelty to others.

More recently, researchers have speculated that other traits may commonly be present along with the dark triad, including psychological entitlement, which is the belief that one is better than others and deserves better treatment, and moral disengagement, which is defined as a style of thinking that enables one to behave unethically without feeling distress.

A recent study published in Psychological Review ( goes further by proposing that the various dark personality traits should be understood as expressions of a single common disposition termed the D-factor, which they define as “the general tendency to maximize one’s individual utility – disregarding, accepting, or malevolently provoking disutility for others, accompanied by beliefs that serve as justifications”.

The team came to this view after reviewing the literature on the various dark traits mentioned above as well as the concepts of self-interest, egoism and spitefulness. The researchers then validated the D-factor model through a series of studies with more than 2500 participants, who were asked to what extent they agreed with statements such as: “It is hard to get ahead without cutting corners here and there”; “It is sometimes worth a little suffering on my part to see others receive the punishment they deserve”; and “I know that I am special because everyone keeps telling me so”. Participants were also asked about instances of and attitudes to aggression, impulsivity and selfish and unethical behaviour. The findings supported the researchers’ thesis that the single D-factor model could be identified underlying the diverse individual traits.

The proposal that varieties of dark personality traits reflect a common factor is analogous to the notion that a broad general intelligence factor underlies performance on a diversity of cognitive tests. It is not suggested that the various dark traits are identical, or always co-occur, and it is acknowledged that different traits (and combinations of traits) may give rise to different behaviours.

However, the authors argue that the concept of a “dark core” may serve as a better predictor of future behaviour than focusing on one or two traits independently. An individual who exhibits one behaviour associated with a dark trait is more likely to also engage in other malevolent behaviours.

The identification of a common factor also invites further research into the relative contribution of nature and nurture to the development of dark traits. While previous research has shown that certain dark traits have a strong genetic component, and environmental factors also contribute, the origins of the underlying D-factor remain to be explored.

A/Prof Tim Hannan is Head of the School of Psychology at Charles Sturt University, and the Past President of the Australian Psychological Society.