The relation between personality and type of error made in multiple-choice examinations when correction for guessing is applied was investigated across two studies. Our general hypothesis was that disinhibited subjects (those scoring high on the Sensitivity to Reward (SR) scale and/or low on the Sensitivity to Punishment (SP) scale) would make more incorrect responses and fewer omission errors (blanks) than inhibited subjects (those with high SP and/or low SR scores). The meta-analyses of 19 examinations in study I confirmed our hypotheses for SP, SR, and extraversion. Regression analyses on effect sizes revealed that SP differences were obtained in examinations with low marks, whereas SR differences were obtained in examinations with more responses and fewer questions. Study 2 showed that a low-mark expectation increased omissions in high-SP subjects, whereas a high-mark expectation increased incorrect responses in high-SR subjects. These results suggest two different mechanisms mediating inhibition/disinhibition: one associated with aversive motivation, and the other with appetitive motivation. Copyright © 2003 John Wiley & Sons, Ltd.