Altruism and behavioral impact on economic decisions became the center of the interest for experimental and behavioral economy. The literature widely reports the results of variety types of dictator games (DG) and cognitive reflection tests (CRT). There is a broad research on donated sum, anonymity of the receiver and dictators’ position (giving vs. taking) in dictator games. Separately research on the CRT evolves from 3 questions to 7 questions variant. However, there is an evident gap in the literature for data that combines these two tools (DG and CRT) in one setup. In this study, we extend existing research on the relationship between cognitive performance on the CRT and dictator decisions taking into account such factors as donated sum, anonymity of the receiver and dictators’ position (giving vs. taking). The main goal is to find out if the cognitive reflection test (CRT) helps to predict rational (or selfish) behavior in a DG. In our investigation, we asked 511 participants to respond to 6 types of dictator games and CRT test. For statistical analysis of the received results, we applied correlation, descriptive statistics, the t-student test and the Mann–Whitney test. Our results show that cognitive reflection was positively correlated with rational (selfish) behavior in DGs. Those dictators who scored high on the CRT (reflective dictators) kept more money for themselves than those who achieved lower scores on the CRT (altruistic, impulsive dictators). Our results confirm an inequity aversion attitude among altruistic, impulsive dictators and selfish, reflective dictators.