Dimensionality, factorial invariance, and cross-cultural differential item functioning of the Short Dark Tetrad (SD4) in Italian, Romanian, and UK samples

The present research tested the dimensionality and cross-cultural differential item functioning of the Short Dark Tetrad (SD4; Paulhus et al., 2021) in samples of university students (total N = 804) from Italy (N = 268), Romania (N = 313), and the United Kingdom (N = 223), respectively. Multidimensional Item Response Theory was used to model the data and ordinal logistic regression for differential item functioning analyses. The results showed that a four-factor model was the best fit for the data. However, the model showed metric non-invariance between the three samples, as well as non-negligible differential item functioning for several items in each of the four factors, in line with findings from previous research on cultural differences in antagonistic traits. Implications for theory and research are discussed.