SENSORY CAPACITIES AND INTELLIGENCE OF DOGS 



tuning forks. Anrep used electric reso- 

 nances and a synchronous motor, driven 

 by alternating current producing, sup- 

 posedly, a sinusoidal curve. As a sound 

 generator in the experimental room a 

 pair of telephones was used. These were 

 placed close together, each attuned to the 

 pitch which it was to transmit. Anrep 

 reports discrimination in the case of one 

 dog of two notes differing but slightly in 

 pitch, the one 637.5 d.v. and the other 

 680. d.v. 



The controversy regarding pitch dis- 

 crimination in the dog can only be 

 settled by further work. 



The only data on the upper limit of the 

 auditory range in the dog come from 

 the Leningrad laboratory (Bourmakin, 

 Andreev). These indicate a sensitivity 

 to sounds far above the highest note 

 audible to man, or up to 100,000 d.v. 

 Other work by Pavlov's students indicates 

 remarkable discriminatory ability for 

 notes alike in pitch but differing in timbre 

 or tone color, and also extreme sensitivity 

 to differences in the periodicity of the 

 beating of a metronome. 



That the dog is able to localize the 

 source of sounds with reasonable accuracy 

 has been demonstrated by Johnson (zo) 

 although he did not study the limits of 

 their sensitivity in this respect. 



Regarding the ability of the dog to 

 respond to the human voice there is a 

 wealth of anecdote but a paucity of 

 experimentation. There is, of course, no 

 question but that they can hear spoken 

 words, but as to the number of spoken 

 words that can be discriminated by a 

 given trained dog there is very little 

 evidence. It has been proven in the case 

 of certain dogs who have been supposed 

 to give differential response to a large 

 number of words that they were merely 

 following a routine, that if the commands 

 were given in an altered order the dog 



would respond as though the original 

 order had been repeated. Don, the talk- 

 ing dog, is the classic example of response 

 to routine (19). A bull terrier, Jasper 

 by name, was claimed by its owner to have 

 an understanding of several hundred 

 words. No thoroughgoing tests were 

 made of the dog, but Watson was in- 

 clined, as a result of observations of his 

 behavior, to consider such a claim far too 

 extravagant. (55, page 315). 



Edinger (9) trained a female Shepherd 

 dog to respond appropriately to a number 

 of simple commands. She could turn the 

 knob of a door and open it. She could 

 also close doors but often confused the 

 two responses, turning the knob of an 

 open door, and so on. If she was told to 

 close a door which was swung open away 

 from her she was quite helpless, not 

 making the response obvious to us of 

 going around behind the door and pushing 

 it shut. Edinger believes that the re- 

 sponses were not given to the spoken 

 commands as words, since nonsense words 

 served just as well if corresponding in- 

 flections were maintained. Schiche (40), 

 on the other hand, believes dogs to be 

 capable of a rather fine degree of discrim- 

 ination of consonants. He trained police 

 dogs to sit at the command of "Setz" and 

 to lie down at the command, "Platz." 

 To such similarly sounding syllables as 

 "seek," "retz," "petz," and "ketz" the 

 dogs did not react. We judge, however, 

 that the experimenter was always present. 



Perhaps the dog for whom the most 

 astounding performances have been 

 claimed is the Airedale, Rolf, often re- 

 ferred to as the dog of Mannheim (xj, 30). 

 This dog was usually present during the 

 daily lessons of some young children. 

 One day while chastizing the children 

 for failing on some simple arithmetical 

 problem the tutor remarked that the 

 problem was so simple that even Rolf 



