SEX DIFFERENCES 33 



of the males that were tested with them at the same time. In this 

 case one female is to be found in each of the following time regions : 

 100 to 120 seconds ; 140 to 160 seconds ; 160 to 180 seconds, and 260 

 to 280 seconds. 



(c) VARIABILITY OP THE SEXES 



An inspection of the probable errors of Table IX. indicates that 

 the behavior of the females was much more variable than that of the 

 males. The table gives in detail the variability of the sexes. In 

 the initial learning period of the maze test the following record was 

 made: mean variation males, 33.5 seconds; mean variation females, 

 53.3 seconds; while in the interference test of ten trials the mean 

 variation for the males was 29.0 seconds; and for the females 56.8 

 seconds. The corresponding records in the retention test gave a mean 

 variation for the males of 21.8 seconds and for the females 59.1 sec- 

 onds. In the multiple choice test the mean variation for the males 

 amounted to 17.0 seconds, while for the females 35.1 seconds. The 

 average of the variations for all the tasks amounted to 25.3 seconds 

 for the males and 51.0 seconds for the females. These figures show 

 that the variability in the behavior of the females was about twice 

 as great as that of the males. 



The above results in sex differences and variations agree with 

 those of Hubbert in her work on habit formation in the albino rat. 13 

 The following is quoted from her results: "The general averages for 

 an equal number of males and females show the males superior to 

 the females in all points save one, that of absolute time. They fin- 

 ished in fewer trials, required less total time, and covered a smaller 

 amount of distance in learning the problem than did the females, 

 while their speed was slightly higher. . . . The mean variation from 

 the time average is less for the males at all ages, their distance varia- 

 tion is less at the age of sixty-five days and three hundred days. ' ' 



Yerkes found that for the behavior of the dancing mouse in the 

 black-white discrimination tests: "The males almost invariably ac- 

 quired a perfect habit quicker than the females . . . (but) ... in 

 the labyrinth test the female is as much superior to the male as the 

 male is to the female in the discrimination tests. ... A degree of 

 proficiency in labyrinth 'B' attained by the males after 7.0 trials was 

 equaled by the females after 6.2 trials. In labyrinth *C' the males 

 acquired a habit as a result of 18.7 trials ; the females, as a result of 

 13.8. And similarly in labyrinth 'D,' 6.1 trials did no more for the 

 males than 2.9 did for the females. ' ' 



13 Hubbert: "The Effect of Age on Habit Formation in the Albino Bat," 

 Behavior Monograph Series, No. 11, 1915. 



