The Mental Life of Monkeys and Apes: A Study of Ideational Behavior

and left

aw in dogs. He has not, I believe, published an account of his work. Subsequently, Franz observed a similar preferenc

e his left hand. He by no means limited himself to this, but in difficult situations he almost invariably reached for food or manipulated objects in connection with food getting w

rl, when driving nails, held the hammer with his left hand and the nail with his right hand. The fact that he never was observed

ing outside the cage I would hold out a peanut to a hungry animal, keeping it so far from the cage that the monkey could barely reach it with its fingers. I noted the hand w

e with his left hand. Only by holding the bait well toward the right side of his body was it possible to induce him to use the right hand.

reaching, he used his right hand seventeen times and his left only three times. It was quite as difficult to induce him to use his left hand for this purpose as

ng experiment consistently used her l

ut it should be said that the results are unsatisfactory because he was at the time

wice. In the second series, given the following day, he used the right hand three time

oratory only a few days previously showed a preference f

ble to use my hands in writing and in various other activities equally well at the age of twelve. I am at present ambidextrous in that there are many things which I do with equal readiness and skill with either hand. Delicate, exact

nd left hand or arm. I should not be at all surprised to discover that it is the rule for animals to possess or to develop readily definite preference for one

inct an

do with social relations seem especially worth reporting. From among them I shall select for desc

nal I

, who on February 27 gave birth to a male infant, I present below the s

rhesus) who has been described by Hamilton (1914, p. 298) as 'Monkey 9, Gertie, M. cynomolgus rhesus (P. irus rhesus). Age, 3 years 2 months. (She is now, May 1,

n occurred Saturday night, and the writer first observed the behavior of the mother the following Monday mor

aining a small shelter box, with an exceptionally quiet and gentle male (not the

hand while she fingered its eyelids and eyes with the other. Scotty sat close beside her watching intently. When disturbed by me the mother carried her infant to a shelf at the top of the cag

s, as well as the female's, keen interest in the body and their frequent examinations of th

the corpse so far decomposed that, with constant handling and licking by the adults, it rapidly wore away. By the third week there remained only the shriveled skin covering a few fragments of bone, and

March 31 there existed only a strip of dry skin about four inc

e. Whenever I approached her cage she scurried into the shelter box and stayed there while I was near. This behavior I never before had observed. It continued for two days. On April

on the floor of the large cage. I picked it up. Gertie evidently noticed my act; for although at a distance of at least ten feet from me, she made a sharp outcry and sprang to the side of the cage n

. It is probable that Gertie had carelessly left it lying on the floor whence it was washed o

mpelled this monkey to carry its gradually vanishing remains about with her and to watch ov

in manuscript, Doctor H

rd her first still-birt

, a baboon, also carried

ek

were futile, for this record of the persistence of maternal behavio

e

fear of the unseen. As I watched and recorded his behavior day after day during the period of most pronounced fear, I could not avoid the thought that the instinctive fear of snakes had something to do with his peculiar actions, and although I have never studied either the natural or the acquired responses of monkeys to snakes, I suspect that lacking such instinctive equipment, Skirrl would have behaved differently as a result of the pricks which he received from the nails. It is needless to redescribe his acquired fear of whiteness as it manifested itself in the freshly painted apparatus. Accompanying these instructive modes of response and their emotions are suggestions of p

mp

ntrasted most strikingly with the more serious, if not

ing him and of stirring him to pursuit or to retaliation were as interesting as they were amusing. Her most common trick was to steal up behind him and pull the hair of his back, or seize his tail with her ha

g attacked. The instant the older animals began to show hostility toward one another she would leap out of the way and watch the disturbance with evident satisfaction. It was this mode of

one in which Jimmie and Gertie were being kept. The

ing and twisting violently, often placing the entire weight of her body on the finger. Her sharp teeth cut to the bone, and it was impossible for the larger and stronger monkey to tear away. For several seconds this continued, then Gertie succeeded in escaping, whereupon she at once retreated to the opposite end of her shelf and proceeded to attend to her injured finger. She cried, wrung her hands, and from time to time placed the finger in her mouth as though in an effort to relieve the pain. By this time Jimmie's attention had been attracted by the disturbance and he rushed up to the shelf, and facing Gertie, watched her intently for a few seconds. The look of puzzled concern on his face was most amusing. Apparently he felt dimly that something in which he should have intelligent interest was going on, but was unable wholly to understand the situation. After watching Gertie for a time and trying

ior of the monkeys. Selfishness seemed everywhere dominant, while clear indications of sympathetic emot

be sure that the spirit of revenge stirred her to punish Gertie so severely. Jimmie's part in the whole affair is, however, perfectly intelligible from our human point of vi