A new study published in Aggression and Violent Behaviour has found that a taste for excitement and risk—sensation seeking—is associated with higher levels of antisocial behaviour, while there is little evidence that resting heart rate itself causes such conduct. The research, led by Timon G. Udo of Vrije Universiteit Amsterdam, analysed data from the Netherlands Twin Register and points to sensation seeking as a potential focal point for future prevention efforts.
Antisocial behaviour refers to actions that break social rules or disregard other people’s rights and feelings. It can include aggression, deceit, rule-breaking, vandalism and violence. High levels of antisocial behaviour during childhood can persist into adulthood and are linked with later criminal behaviour and other harmful outcomes.
For decades, researchers have noted a relationship between antisocial behaviour and resting heart rate—the number of heartbeats per minute when a person is calm. People with lower resting heart rates have often been found to show more antisocial behaviour. Explanations offered include that a low heart rate may create an uncomfortable feeling of under-stimulation, prompting some individuals to seek intense experiences, or that a low heart rate reflects lower fear or inhibition, making risky or harmful acts less difficult.
Sensation seeking describes a strong preference for varied, novel and intense experiences, along with a willingness to take risks to obtain them. Previous studies have linked sensation seeking with aggression and rule-breaking, but most were observational. A major aim of the new study was to determine if sensation seeking mediates—the bridging mechanism for—the established link between resting heart rate and antisocial behaviour.
The research, conducted by Udo and colleagues, used data from the Netherlands Twin Register. The broad sample included 8,422 adults (66.4% female, average age 41.9 years). The team also examined 1,927 fraternal twins (67.1% female, average age 32.45 years) and a separate group of 2,599 identical twins (74.3% female, average age 34.73 years).
Participants completed questionnaires measuring antisocial behaviour and sensation seeking. Because direct resting heart rate measurements were not available, the researchers employed polygenic scores—an estimate of genetic predisposition based on multiple genes—associated with resting heart rate as an indirect proxy. They then used statistical models to compare differences between families and differences between twins within the same family.
In the broad sample, individuals with higher sensation-seeking scores also tended to report more antisocial behaviour. This pattern persisted in analyses of fraternal twins and identical twins. A significant within-family relationship remained even among identical twins, who share their entire genetic makeup, suggesting a possible causal contribution from sensation seeking, though the study could not establish causality.
The evidence for resting heart rate was less conclusive. The genetic proxy for resting heart rate predicted antisocial behaviour in the broad sample, but in an unexpected direction: a genetic tendency toward a higher resting heart rate was linked to more antisocial behaviour. The relationship disappeared in the fraternal-twin analysis, and the proxy did not predict sensation seeking. The researchers therefore found no evidence that sensation seeking mediated a resting heart rate relationship.
Udo and colleagues concluded that sensation seeking “could therefore be an effective target for antisocial behaviour interventions, regardless of resting heart rate.” They cautioned that this does not mean sensation seeking should simply be suppressed; safer activities could potentially provide stimulation without involving antisocial behaviour.
The study noted several important limitations. Resting heart rate was not measured directly, and the genetic proxy captured only part of the factors influencing it. Antisocial behaviour and sensation seeking were assessed via self-report questionnaires. Additionally, participants generally scored very low on antisocial behaviour, which may limit applicability to more severely antisocial populations, and the study could not definitively confirm the direction of causality.
The research, titled Adventurous and antisocial hearts: Investigating the causality of associations between antisocial behaviour, resting heart rate and sensation seeking, was authored by Timon G. Udo, Susanne Bruins, René Pool and Camiel M. van der Laan.
