Fig. 1.

Visual representation of the study aims. In all models, summary statistics for individual impulsive personality traits (IPTs) are represented by squares, latent factors are represented by ovals, single-headed arrows indicate factor loadings, and double-headed arrows indicate correlations. Aim 1 was to evaluate whether the five IPTs were captured by separate genetic factors or whether certain facets could be collapsed together (e.g., positive and negative urgency, and lack of perseverance and lack of premeditation, as in Cyders & Smith, 2007). In these models, UPPS-P subscales were initially modeled as separate factors, with the Barratt Impulsiveness Scale (BIS) total score loading on the lack-of-premeditation factor. Extraversion was included as a second indicator of sensation seeking to aid in model fit (see the Supplemental Material available online). Aims 2 and 3 were evaluated simultaneously by adding delay discounting and internalizing psychopathology in the same model to provide the maximum information in the genetic-correlation matrix. Aim 2 evaluated whether genetic influences on delay discounting were best modeled as an independent genetic factor or a facet of lack of premeditation. Aim 3 was to evaluate the hypothesis that a latent factor capturing genetic influences on internalizing psychopathology would be most strongly genetically correlated with IPT genetic factors related to control over emotion-based rash action (positive urgency, negative urgency, or their combination, depending on Aim 1). Genetic correlations among IPTs are shown in gray for simplicity. Thicker black arrows indicate stronger hypothesized correlations. NU = UPPS-P Negative Urgency subscale; PU = UPPS-P Positive Urgency subscale; Prem = UPPS-P Lack of Premeditation subscale; Pers = UPPS-P Lack of Perseverance subscale; SS = UPPS-P Sensation Seeking subscale; Extr = extraversion; MDD = major depressive disorder; Neur = neuroticism; SWB = subjective well-being.