Detecting socially desirable responding with the Personality Assessment Inventory: the Positive Impression Management scale and the Defensiveness Index.

In order to assess the effectiveness of the validity scales from the Personality Assessment Inventory (PAI; Morey, 1991), 111 Introductory Psychology students completed the Positive Impression Management scale (PIM) and the Defensiveness Index (DEF) from the PAI along with the Balanced Inventory of Desirable Responding (BIDR; Paulhus, 1984) under two instructional sets: 'forthright" and "fake good." Both PAI measures of socially desirable responding were superior to the BIDR scales at identifying protocols written under the fake good instructions. Contrary to Morey (1991), the results from this study support the use of a raw score of 18 as the cut-off on the PIM scale rather than 23. Using 18 as the criterion, 85.1% of cases were correctly classified. A cut-off score for the DEF (5) was derived and tested. Using this criterion resulted in the correct classification of 83.3% cases. A discriminant function that incorporated both the PAI indices produced no substantial improvement in classification accuracy.