Even though there is an increasing interest in response styles, the field lacks a systematic investigation of the bias that response styles potentially cause. Therefore, a simulation was carried out to study this phenomenon with a focus on applied settings (reliability, validity, scale scores). The influence of acquiescence and extreme response style was investigated, and independent variables were, for example, the number of reverse-keyed items. Data were generated from a multidimensional item response model. The results indicated that response styles may bias findings based on self-report data and that this bias may be substantial if the attribute of interest is correlated with response style. However, in the absence of such correlations, bias was generally very small, especially for extreme response style and if acquiescence was controlled for by reverse-keyed items. An empirical example was used to illustrate and validate the simulations. In summary, it is concluded that the threat of response styles may be smaller than feared.