GROUP BEHAVIOR 159 



train all at the same time the rate of learning was 

 retarded. Paired fish reacted as well as if they had 

 been isolated, but the reactions of groups of four 

 were slowed down, and those of ten even more so. 

 Two fish would rarely jump at once, and when some 

 one individual was getting set to jump for the food 

 under the red light, another would frequently come 

 along and give him a jab in the belly which would 

 stop all tendency to jump for the time. 



One more instance remains to be reported. Dr. 

 Welty, who has been mentioned before, undertook 

 to train goldfish to move forward from the rear 

 screened-off portion of an aquarium through a door 

 into a small forward chamber where each was fed 

 just after it came through the opening. (118) An 

 aquarium-maze, similar to those used, is shown in Fig- 

 ure 31. The signal to the fish that it was time to 

 react came from increasing the intensity of light in 

 the aquarium and opening the door between the two 

 compartments. Under Dr. Welty's careful coaching 

 the fish improved rapidly in their speed of reaction 

 and usually had reached a good level of performance 

 by the sixth day of training. 



In his experiments almost a thousand fishes were 

 trained at one time or another. The results of a 

 sample experiment are recorded in Figure 32. In this 

 test there were eight goldfish, each isolated in indi- 



