Impulsive behavior and stimulus-response variability in choice reaction time

In two studies involving 138 unselected undergraduates, we investigated the idea that impulsivity is linked to a reflexive style of information processing. Using the Stroop test, we calculated the standard deviation of response times and found that this measure was negatively correlated with both trait impulsivity (Study 1) and the likelihood of impulsive behavior in daily life (Study 2). We suggest that: (a) impulsive people favor a more reflexive style of responding to environmental stimuli and (b) standard deviations may supplement other cognitive processing measures (e.g., RT and accuracy) in understanding the relation between impulsivity and behavior.