Project Gutenberg's The Mental Life of Monkeys and Apes, by Robert M. Yerkes

This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.net

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

Author: Robert M. Yerkes

Release Date: January 27, 2004 [EBook #10843]

Language: English

*** START OF THIS PROJECT GUTENBERG EBOOK MENTAL LIFE OF MONKEYS ***

Produced by Michael Oltz and PG Distributed Proofreaders

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

        ROBERT M. YERKES
       Harvard University

       BEHAVIOR MONOGRAPHS
    Volume 3, Number 1, 1916
        Serial Number 12
    Edited by JOHN B. WATSON
  The Johns Hopkins University

WITH SIX PLATES AND FIVE TEXT FIGURES

CONTENTS

I. Interests, opportunity and materials

II. Observational problems and methods

III. Results of multiple-choice experiments:

1. Skirrl, Pithecus irus 2. Sobke, Pithecus rhesus 3. Julius, Pongo pygmaeus

IV. Results of supplementary tests of ideational behavior:

    1. Julius, Pongo pygmaeus:
        Box stacking experiment
        Box and pole experiment
        Draw-in experiment
        Lock and key test
    2. Skirrl, Pithecus irus:
        Box stacking experiment
        Box and pole experiment
        Draw-in experiment
        Hammer and nail test
        Other activities
    3. Sobke, Pithecus rhesus:
        Box stacking experiment
        Draw-in experiment
        Box and pole experiment
        Other activities

V. Miscellaneous observations:

    1. Right- and left-handedness
    2. Instinct and emotion:
        Maternal instinct
        Fear
        Sympathy

  VI. Historical and critical discussion of ideational behavior in
      monkeys and apes:

    1. Evidences of ideation in monkeys
    2. Evidences of ideation in apes

 VII. Provision for the study of the primates and especially the monkeys
      and anthropoid apes

VIII. Bibliography

I

INTERESTS, OPPORTUNITY AND MATERIALS

Two strong interests come to expression in this report: the one in the study of the adaptive or ideational behavior of the monkeys and the apes; and the other in adequate and permanent provision for the thorough study of all aspects of the lives of these animals. The values of these interests and of the tasks which they have led me to undertake are so widely recognized by biologists that I need not pause to justify or define them. I shall, instead, attempt to make a contribution of fact on the score of each interest.

While recognizing that the task of prospecting for an anthropoid or primate station may in its outcome prove incomparably more important for the biological and sociological sciences and for human welfare than my experimental study of ideational behavior, I give the latter first place in this report, reserving for the concluding section an account of the situation regarding our knowledge of the monkeys, apes, and other primates, and a description of a plan and program for the thorough-going and long continued study of these organisms in a permanent station or research institute.

In 1915, a long desired opportunity came to me to devote myself undividedly to tasks which I have designated above as "prospecting" for an anthropoid station and experimenting with monkeys and apes. First of all, the interruption of my academic duties by sabbatical leave gave me free time. But in addition to this freedom for research, I needed animals and equipment. These, too, happily, were most satisfactorily provided, as I shall now describe.

When in 1913, while already myself engaged in seeking the establishment of an anthropoid station, I heard of the founding of such an institution at Orotava, Tenerife, the Canary Islands, I immediately made inquiries of the founder of the station, Doctor Max Rothmann of Berlin, concerning his plans (Rothmann, 1912).[1] As a result of our correspondence, I was invited to visit and make use of the facilities of the Orotava station and to consider with its founder the possibility of coöperative work instead of the establishing of an American station. This invitation I gratefully accepted with the expectation of spending the greater part of the year 1915 on the island of Tenerife. But the outbreak of the war rendered my plan impracticable, while at the same time destroying all reasonable ground for hope of profitable coöperation with the Germans in the study of the anthropoids. In August, 1915, Doctor Rothmann died. Presumably, the station still exists at Orotava in the interests of certain psychological and physiological research. So far as I know, there are as yet no published reports of studies made at this station. It seems from every point of view desirable that American psychologists should, without regard to this initial attempt of the Germans to provide for anthropoid research, further the establishment of a well equipped American station for the study not only of the anthropoid apes but of all of the lower primates.

[Footnote 1: See bibliography at end of report.]

In the early months of the war while I was making every effort to obtain reliable information concerning conditions in the Canary Islands, I received an urgent invitation from my friend and former student, Doctor G. V. Hamilton, to make use of his collection of animals and laboratory at Montecito, California, during my leave of absence from Harvard. This invitation I most gladly accepted, and in February, 1915, I established myself in Santa Barbara, in convenient proximity to Doctor Hamilton's private laboratory where for more than six months I was able to work uninterruptedly under nearly ideal conditions.

Doctor Hamilton without reserve placed at my disposal his entire collection of animals, laboratory, and equipment, provided innumerable conveniences for my work, and in addition, bore the entire expense of my investigation. I cannot adequately thank him for his kindness nor make satisfactory acknowledgment here of his generous aid. Thanks to his sympathetic interest and to the courtesy of the McCormick family on whose estate the laboratory was located, my work was done under wholly delightful conditions, and with assistance from Ramon Jimenez and Frank Van Den Bergh, Jr., which was invaluable. The former aided me most intelligently in the care of the animals and the construction of apparatus; and the latter, especially, was of very real service in connection with many of my experiments.

The collection of animals which Doctor Hamilton placed at my disposal