EXPERIMENTS AND OBSERVATIONS ^^ 



in controlling my signals so as to get the inverted order 

 in the horse's response. In the case of Mr. Schillings and 

 of Mr. von Osten all of the movements just described 

 were very minute, and long after the movements, which 

 were effective stimuli for releasing the process of tapping, 

 were recognized, it was still exceedingly difificult to dis- 

 cover them in these two gentlemen. The signal for 

 " zero " and " no " was relatively the most pronounced of 

 the group in the case of Mr. von Osten, while with Mr. 

 Schillings it was the least pronounced, in comparison with 

 his very strong "jerk". Yet in both cases Hans re- 

 sponded wtih absolute certainty. 



It is now readily conceivable how it was possible to 

 make the horse respond to all sorts of foolish questions, 

 both by involuntary signs — i. e., expressions following 

 upon the bare imaging of the response expected, — as well 

 as by means of controlled signs. One could thus obtain 

 consecutively the answers " yes " and " no " to the same 

 question. Or one might ask : " Hans, where is your 

 head ? ", and Hans would bend to the earth. " And 

 where are your legs ? " He would look at the skies. Etc. 



Let us examine for a moment the directives which the 

 horse required for the various positions. If one called 

 him, while he was running about the courtyard, he paid 

 no attention whatever, but if one beckoned to him, he 

 came immediately. A raising of the hand brought him 

 to a standstill. If one now stepped forward or pointed 

 one's hand in that direction, he would step forward, or 

 vice versa, he would step backward. By means of mini- 

 mal movements of the head, of the arm nearest the 

 horse, or of the whole body, Hans could be induced to 

 assume the position one desired, without touching him or 

 speaking a word. I noticed this quite early in the course 



