1-4 5-8 9-12 13-16 17-20 21-24 



DAYS 



Fig. 10. Per cent errors for each sex on successive 4 day periods of delayed re- 

 sponse training. 



O MALE 

 • FEMALE 



12 3 4 5 



PROBLEMS 



Fig. 1 1 . Mean errors for each sex on each of the five dot-discrimination problems. 



741 



