This article presents a study on interference in serial verbal reactions, focusing on the effects of color and word stimuli on reading and naming colors. The research was conducted at the Jesup Psychological Laboratory at George Peabody College for Teachers. The study involved three experiments, each designed to examine the interference effects of conflicting stimuli on verbal responses. In Experiment 1, the effect of interfering color stimuli on reading color names was investigated. The results showed that reading color names printed in colors different from those named by the words took significantly longer than reading the same names printed in black. However, this difference was not statistically reliable. The study also found that the interference effect varied between males and females, with females showing slightly better performance. In Experiment 2, the effect of interfering word stimuli on naming colors was examined. The results indicated that naming colors when the color of the print was different from the word's name caused a significant increase in time compared to naming colors when the print color matched the word's name. This interference effect was more pronounced and reliable, with a 74% increase in time for naming colors. The study also found that females performed slightly better than males in naming colors. In Experiment 3, the effects of practice on interference were studied. The results showed that practice reduced the interference effect of conflicting word stimuli on naming colors but did not eliminate it. Practice also produced a learning curve similar to those observed in other learning experiments. Additionally, practice increased the variability of responses among subjects. The study found that practice on the NCWd test (naming colors when the print color is different from the word's name) increased individual differences, while practice on the RCNd test (reading color names when the print color is different from the word's name) decreased individual differences. The study concluded that the difference in speed between reading color names and naming colors may be attributed to differences in training. The word stimulus was associated with the specific response of reading, while the color stimulus was associated with various responses, including naming. The study also found that the sex difference in naming colors may be due to differences in the training of the two sexes. Overall, the study highlights the complex nature of interference in serial verbal reactions and the role of practice in modifying these effects.This article presents a study on interference in serial verbal reactions, focusing on the effects of color and word stimuli on reading and naming colors. The research was conducted at the Jesup Psychological Laboratory at George Peabody College for Teachers. The study involved three experiments, each designed to examine the interference effects of conflicting stimuli on verbal responses. In Experiment 1, the effect of interfering color stimuli on reading color names was investigated. The results showed that reading color names printed in colors different from those named by the words took significantly longer than reading the same names printed in black. However, this difference was not statistically reliable. The study also found that the interference effect varied between males and females, with females showing slightly better performance. In Experiment 2, the effect of interfering word stimuli on naming colors was examined. The results indicated that naming colors when the color of the print was different from the word's name caused a significant increase in time compared to naming colors when the print color matched the word's name. This interference effect was more pronounced and reliable, with a 74% increase in time for naming colors. The study also found that females performed slightly better than males in naming colors. In Experiment 3, the effects of practice on interference were studied. The results showed that practice reduced the interference effect of conflicting word stimuli on naming colors but did not eliminate it. Practice also produced a learning curve similar to those observed in other learning experiments. Additionally, practice increased the variability of responses among subjects. The study found that practice on the NCWd test (naming colors when the print color is different from the word's name) increased individual differences, while practice on the RCNd test (reading color names when the print color is different from the word's name) decreased individual differences. The study concluded that the difference in speed between reading color names and naming colors may be attributed to differences in training. The word stimulus was associated with the specific response of reading, while the color stimulus was associated with various responses, including naming. The study also found that the sex difference in naming colors may be due to differences in the training of the two sexes. Overall, the study highlights the complex nature of interference in serial verbal reactions and the role of practice in modifying these effects.