1028 C.A. Brinkley et al. / Personality and Individual Di€erences 31 2001) 1021±1038 when an S was present, they received feedback consisting <strong>of</strong> the presentation <strong>of</strong> a low-pitched tone, a message that they had lost 10 cents, and the removal <strong>of</strong> a poker chip. No rewards or punishments were administered in the absence <strong>of</strong> a response. Performance on the passive avoidance task is evaluated by looking at two di€erent types <strong>of</strong> errors. Commission errors are de®ned as failures to inhibit responses to S stimuli and omission errors are de®ned as failures to respond to S+ stimuli. Errors <strong>of</strong> commission represent failures <strong>of</strong> passive avoidance and have di€erentiated PCL-R de®ned psychopaths and controls in past research. As the task requires that participants observe all stimuli before performance can re¯ect learning, data from the ®rst block <strong>of</strong> trials are not analyzed. Following Newman and Schmitt 1998) and Lynam et al. 1999), it was hypothesized that low-anxious psychopaths de®ned using either the PCL-R or the SRPS) would make more commission errors than low-anxious controls. Although some <strong>of</strong> the passive avoidance data has been previously presented in Newman and Schmitt 1998), we felt the comparisons between the performances <strong>of</strong> SRPS and PCL-R de®ned psychopaths and controls on this task was su ciently interesting and important to warrant <strong>report</strong>ing the data here as well. It should be noted that the data sets for the two papers are slightly di€erent because participants included in Newman and Schmitt's study who did not have SRPS scores were excluded from the present analyses. 2. Results 2.1. Con®rmatory factor analyses Con®rmatory factor analyses CFAs) were conducted to determine the adequacy <strong>of</strong> ®t <strong>of</strong> a two-factor model for the SRPS as identi®ed by Levenson et al. 1995). For the two-factor model, each item was constrained to load on only one <strong>of</strong> the two factors 16 items loading on the SRPS primary scale and 10 items loading on the SRPS secondary scale) and latent factors were allowed to correlate. Fit indices used to determine goodness-<strong>of</strong>-®t included the comparative ®t index CFI; Bentler, 1990), the root mean square error <strong>of</strong> approximation RMSEA; Browne & Cudeck, 1993), and the Bentler and Bonett 1980) non-normed ®t index NNFI). Values for CFI and NNFI above 0.9 are indicative <strong>of</strong> good ®t; an RMSEA value <strong>of</strong> 0.05 or smaller is indicative <strong>of</strong> good ®t whereas RMSEA values between 0.05 and 0.08 indicate a reasonable model ®t Browne & Cudeck, 1993). Model improvements were tested by means <strong>of</strong> change in model chi-square w 2 ). In order to test the comparability <strong>of</strong> the SRPS item-factor relations across the Caucasian and African-American samples, two-factor CFA invariance models were ®t to the data. Prior to invariance modeling, the ®t <strong>of</strong> the Levenson et al. 1995) two-factor model was examined for each race separately to establish good-®tting baseline models Byrne, 1994). When Lynam et al. 1999) conducted two-factor CFAs <strong>of</strong> the SRPS using data from college undergraduates, model ®t was found to be poor unless several errors <strong>of</strong> measurement were allowed to correlate and one item was allowed to load on both factors ``Love is overrated``). In the current study, initial two-factor CFAs were computed without specifying the Lynam et al. 1999) model modi®cations correlated errors and one item loading on both factors) and these analyses revealed poor model ®t for both Caucasians CFI=0.85, NNFI=0.83, RMSEA=0.06) and African-Americans CFI=0.79, NNFI=0.77, RMSEA=0.08). Adding the model modi®cations
identi®ed by Lynam et al. 1999) signi®cantly improved model ®t for both Caucasians CFI=0.90, NNFI=0.88, RMSEA=0.05; w 2 df=18)=90.95, P
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