The distinct peer-based perspectives of deviant normative influence and unstructured/unsupervised socializing with friends contend that adolescents rely on different information when deciding to offend, with the former positing that individuals offend after considering the longer term consequences of behavior, and the latter positing that decisions to offend derive from situational stimuli. We argue that these processes can be organized under a dual-systems framework of decision making, which leads to the hypothesis that individuals at the edges of impulsivity should be differentially vulnerable to these peer influence processes because of their tendency to rely on only one system of decision making. We use two large data sets to test this hypothesis: a nationally representative sample of adolescents from the AddHealth study (N = ∼9,000) and a pooled panel data set of adolescents from the Gang Resistance Education and Training (G.R.E.A.T.) evaluation (N = 1,172). The results of longitudinal negative binomial analyses indicate that normative influence by deviant peers has a stronger effect on delinquency for adolescents with low impulsivity than it does for individuals with high impulsivity. Differences in the informal socializing with peers coefficients are less clear and offer minimal support for our predictions.