Prediction of self- and observer report scores on HEXACO-60 and NEO-FFI scales

•Self- and observer reports on the NEO-FFI and HEXACO-60 were examined.•The HEXACO-60 adequately predicted all of the NEO-FFI scales.•The NEO-FFI did not adequately predict HEXACO Honesty–Humility and Emotionality.•The NEO-FFI contained larger source-specific variance than the HEXACO-60.

We investigated the validity of two personality inventories—the NEO-FFI and HEXACO-60—in predicting scores on each of the factor scales of the other instrument, both within and between sources of data. We also examined the extent to which the source-specific variances of the scales of each inventory are attributable to a common factor of response bias. Results (N = 660) showed that the HEXACO-60 scales collectively predicted all of the NEO-FFI scales rather well, but that the NEO-FFI scales showed limited validity in predicting HEXACO-60 Honesty–Humility and Emotionality. Also, the NEO-FFI scales contained considerably larger source or bias factors (especially in self-report) than did the HEXACO-60 scales. We discuss implications for studies of the predictive validities of the instruments.