How response bias affects the factorial structure of personality self-reports.

Background: Various studies have shown that acquiescence can distort the factor structure of personality questionnaires based on the five-factor model.  In the present study, we analysed how acquiescence and social desirability affect the factor structure of a measure based on this personality model and a measure of aggression.

Method: We analysed the factor structures of both tests before and after removing both biases in a sample of 532 adolescents aged between 11 and 18 (M= 14.75, SD= 2.1).

Results: The factor structure of both tests presented a worse fit to the expected model when response bias was not controlled, and the congruence indexes for the personality and aggression measures showed a moderate (from C= .948 to C= .872) or great (from C= .931 to C= .475) decrease, respectively. Furthermore, acquiescence was largely responsible for these effects, and social desirability effects were only shown on the aggression measure.

Conclusions:   Response bias, and especially acquiescence, should be controlled during the development of personality measures to avoid distorting them, especially with samples of people with a high level of acquiescence (for example, those with little education, the young or the elderly). Furthermore, the use of response bias loadings as a criterion for choosing the items minimizes those distortions.