212 



SEX DIFFERENCES IN COLOR PERCEPTION 



senting the average error of displacement and the ordinates the number 

 of cases. 



In the discrimination of the grays the results are as indicated in the 

 following table: 



Women are here, as in the colors, decidedly superior to the men, the 

 average displacements being 2.1 and 1.5. In the variability the 

 difference is insignificant, the coefficients of variation showing a some- 

 what greater variability in women. In range, men run from an average 

 error of displacement of 1 . 2 to 3 . 9, and women from o . 4 to 2 . 7. 



The experiments on discriminative sensibility to the grays were 

 primarily made to determine the correlation between ability in dis- 

 criminating colors and grays. The number of cases is too small, how- 

 ever, to determine the amount of correlation with a high degree of 

 validity but the Pearson coefficient of correlation 1 is given for what it is 

 worth. 



Men +0.67 

 Women +0.30 



There is evidently a high correlation between discriminative sensi- 

 bility in the colors and the grays. This may point to a genuine relation- 

 ship between the two abilities or it may be, and doubtless is partly, a 

 correlation in conscientiousness in making the experiments. In all 

 group tests this is no doubt a factor in determining the amount of corre- 

 lation and one which cannot well be measured or allowed for. It is of 

 course possible that there is a close relationship between discriminative 

 sensibility in different sense departments but it could be satisfactorily 

 measured only on the assumption that equal interest and effort were 

 displayed in the tests from which the correlation is determined. 



Calculated by the formula 





txy being the sum of the products of the deviations and rc6'6 J the 



product of the number of cases and the standard deviations of the two abilities. A correlation+i.oo would 

 mean perfect positive correlation, 0.00, the absence of correlation and — 1.00 perfect inverse correlation. 



