The A-RSQ was completed by 685 adults in an internet survey. Scores (M = 8.6, SD= 3.6, range = 1.0–24.2, a = .70) did not systematically vary with gender or age (range 18–78, M = 25.6 years), but were inversely associated with years of education (r = .15; p < .001). Controlling for education, the A-RSQ showed expected correlations (all p < .001) with related constructs measured in a subsample of survey respondents (n = 245), including: neuroticism (John, Donahue, & Kentle, 1991, r = .32); social avoidance/distress (Watson & Friend, 1969, r = .34); self-esteem (Rosenberg, 1965, r = .46); attachment anxiety and attachment avoidance (Fraley, Waller, & Brennan, 2000; r = .48 and r = .33, respectively); and interpersonal sensitivity and depression (Derogatis, Lipman, & Covi, 1973,r = .45 and r = .37, respectively). As evidence for its discriminant validity, the A-RSQ remained associated with attachment anxiety (r = .21, p < .001) and interpersonal sensitivity (r = .18, p < .01) when controlling for the rest of these constructs. Further support for the validity of the A-RSQ derives from its ability to reﬂect the individual differences in RS associated with serious forms of psychopathology in which rejection concerns are prominent. In an ongoing study of adults who met diagnostic criteria for borderline and/or avoidant personality disorders (n = 80), the mean A-RSQ scores for those diagnosed with either one of the disorders fell above the 90th percentile for our unselected internet sample, whereas the mean A-RSQ scores for those diagnosed with both disorders fell above the 99th percentile (Downey, Berenson, & Rafaeli, 2009). Hence, the A-RSQ captures meaningful differences in RS across diverse groups of adults.