According to Gottfredson and Hirschi's (1990) A General Theory of Crime, all illegal activity is the manifestation of a single underlying cause. The authors argue that inadequate child-rearing causes individuals to develop a similar type of propensity for criminal and analogous behavior. Gottfredson and Hirschi label this characteristic "low self-control." Six dimensions, which can be identified in their theory, are suggested to comprise a final low self-control trait. Further, low self-control is proposed to be an invariant characteristic (i.e., its form does not change with the age of the individual or context in which the person resides). In this research, we evaluate these two propositions. First, the six dimensions are measured and used to determine if a multidimensional model can explain another common factor-low self-control-in two samples of individuals (from different locales) with dissimilar mean ages. Second, low self-control in both samples is tested for invariance. We test the proposed invariance of low self-control by examining if the parameter values in a model, which is reflective of Gottfredson and Hirschi's conceptualization of the characteristic, differ across the two samples of individuals. The results support both of Gottfredson and Hirschi's propositions. Low self-control does appear to be a multi-dimensional characteristic whose dimensions represent another common factor. Low self-control also appears to be an invariant latent trait that members of these two samples possess. These tests help to clarify Gottfredson and Hirschi's conceptualization of low self-control.