Abstract

Purpose: Previous research has linked poor sleep quality to aggressive behaviour, with cognition clearly implicated. A separate strand of research has shown that presenting participants with misinformation about the quality of their sleep may affect task performance. Consequently, we investigated the question of whether misleading participants about their sleep could also affect aggressive responses.
Methodology: Through a bogus sleep quality diagnosis procedure, participants were led to believe that they had either slept well or slept poorly during the previous night. Aggression was measured using the Tangrams Help/Hurt Task (THHT) and potential differences between groups according to misinformation was assessed.
Findings: Overall, participants who were told they had slept poorly showed more aggressive responses than those who were told they had slept well. Further analyses indicated that on this task, the effect of sleep misinformation was based on reducing prosocial behaviour rather than increasing hurtful behaviour. Thus, manipulating sleep beliefs may offer a simple route to shaping aggressive and prosocial responses.
Originality: This research elucidates our understanding of the relationship between sleep and aggressive/prosocial behaviour by demonstrating, for the first time, the moderating role of cognition and belief. Beliefs about sleep may directly influence aggressive behaviour, suggesting that even simple changes in these beliefs may help shape how people act. However, it remains unclear whether individuals must be consciously aware of the link between sleep and aggression for this effect to emerge.