HighlightsImpulsivity is not a unitary construct and instead comprises dissociable subtypes.Reflection-impulsivity is a distinct and well-defined facet of impulsivity.Additional characterisations of motor-impulsivity are required.Several tasks purported to index impulsivity should be treated with caution.Researchers should employ multiple measures of types of impulsivity simultaneously.

These data suggest that the effects of alcohol on the subtypes of impulsivity are dissociable. Motor impulsivity is sensitive to the pharmacological effects of alcohol, whereas the reflection subtype is affected by cognitive alcohol expectancies. The findings have implications for the understanding of impulsive behaviour under the influence of alcohol.

The study applies a comprehensive selection of behavioural and self-report measures of impulsivity and indicates that excessive drinkers are more impulsive in some but not all aspects. The results indicate that the wide range of deficits apparent in alcohol-dependent individuals are not evident in this younger, heavy drinking population, but that specific performance and self-identified deficits are already apparent.