Optimal combination of personality and intelligence

Personality and intelligence are both related to job performance, but how should they be weighted for optimal results? The most straightforward approach is a linear combination, and indeed there is little evidence for other types of models. Once this is decided the final question is what weights should be given to the two types of information, in order to maximize predictive efficiency. It is well-known that they tend to be uncorrelated, hence the crucial question is how valid they are in relation to job performance criteria. Intelligence, or GMA (the g factor) correlates around 0.6 with job performance (Schmidt & Hunter, 1998). "Personality" is a less stringent term, and could mean many things. However, I shall take personality as referring to an optimal index of subscales, and such indices have been found to correlate around 0.55 with job performance (de Colli, 2011; Sjöberg, 2010; Sjöberg, Bergman, Lornudd, & Sandahl, 2011), after correction for measurement errors in criteria and range restriction in the independent variable (Schmidt, Shaffer, & Oh, 2008). Hence, intelligence and personality, in this sense, are equally efficient as predictors and an evidence-based strategy is to treat them that way, with equal weights.

It should be noted that the usual Big Five dimensions are much weaker predictors of job performance, as shown in a number of meta-analyses (Barrick, Mount, & Judge, 2001). To get an efficient personality predictor it is necessary to form an index based on focused and narrow scales (Bergner, Neubauer, & Kreuzthaler, 2010; Christiansen & Robie, 2011; Sjöberg, 2010/2012). Big Five personality tests are not sufficient for optimal prediction of job performance.

References

Barrick, M. R., Mount, M. K., & Judge, T. A. (2001). Personality and performance at the beginning of the new millennium: What do we know and where do we go next? International Journal of Selection and Assessment, 9, 9-30.

Bergner, S., Neubauer, A. C., & Kreuzthaler, A. (2010). Broad and narrow personality traits for predicting managerial success. [doi:10.1080/13594320902819728]. European Journal of Work and Organizational Psychology, 19, 177-199.

Christiansen, N. D., & Robie, C. (2011). Further consideration of the use of narrow trait scales. [doi:10.1037/a0023069]. Canadian Journal of Behavioural Science/Revue canadienne des sciences du comportement, 43, 183-194.

de Colli, D. (2011). Ett nytt svenskt arbetspsykologiskt test och arbetsprestation inom polisen – samtidig validitet: Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.

Schmidt, F. L., & Hunter, J. E. (1998). The validity and utility of selection methods in personnel psychology: Practical and theoretical implications of 85 years of research findings. Psychological Bulletin, 124, 262-274.

Schmidt, F. L., Shaffer, J. A., & Oh, I.-S. (2008). Increased accuracy for range restriction corrections: Implications for the role of personality and general mental ability in job and training performance. Personnel Psychology, 61, 827-868.

Sjöberg, L. (2010). Upp-testet och kundservice: Kriteriestudie. Forskningsrapport 2010:6. Stockholm: Psykologisk Metod AB.

Sjöberg, L. (2010/2012). A third generation personality test (SSE/EFI Working Paper Series in Business Administration No. 2010:3). Stockholm: Stockholm School of Economics.

Sjöberg, L., Bergman, D., Lornudd, C., & Sandahl, C. (2011). Sambandet mellan ett personlighetstest och 360-graders bedömningar av chefer i hälso- och sjukvården. Stockholm: Karolinska Institutet, Institutionen för lärande, informatik, management och etik (LIME).