Adult Rhesus Monkeys do not Copy the Choices of a Conspecific Shown in Videos Restricted; Files Only

Nasrini, Jad (Fall 2021)

Permanent URL:


Evidence of socially learned animal traditions has accumulated from mostly observational field studies. In contrast, laboratory experiments with monkeys often fail to find the social learning thought to be necessary for animal traditions to form in the wild. We investigated social learning by presenting Rhesus monkeys with videos of a conspecific solving two-choice discrimination tasks. With training, monkeys gradually learned to correctly follow videos of a demonstrator, however, follow-up experiments revealed that this accuracy improvement was not due to copying the behavior of the demonstrator monkey. In generalization tests with videos that were horizontally reversed, monkeys continued responding to the location they had associated with each video, rather than matching the new choice location shown in the mirrored video. When the task was changed to make location irrelevant, such that monkeys could choose correctly only by selecting the same image selected by the demonstrator in the video, they did not exceed chance over 12,000 training trials. Because monkeys readily learn to follow nonsocial visual cues to guide image choice, their inability to copy a demonstrator here indicates substantial limitations in the capacity for social learning in monkeys. Furthermore, these findings encourage deeper consideration of what monkeys perceive when presented with video stimuli on computer screens.

Table of Contents

1. Introduction 1

2. Subjects & Materials 2

2.1. Subjects & testing environment 2

2.2. Video stimuli 3

2.3. Statistical Analyses 4

3. Experiment 1: Monkeys did not spontaneously copy the choices made by a conspecific demonstrator 4

3.1. Procedure 5

3.2. Results & Discussion 6

4. Experiment 2: Monkeys learned to use information in videos to guide choice when no other solution was available. 7

4.1. Procedure 8

4.2. Results & Discussion 8

5. Experiment 3: Tests with horizontally mirrored videos showed that monkeys learned something other than “copy the demonstrator” 10

5.1. Procedure 11

5.2. Results & Discussion 14

6. Experiment 4: Monkeys did not copy the image choice of a demonstrator even after training 16

6.1. Procedure 16

6.2. Results & Discussion 17

7. Experiment 5: Monkeys chose the location depicted in demonstrator videos 19

7.1. Procedure 20

7.2. Results & Discussion 20

8. Experiment 6: A replication of probe trials with horizontally mirrored videos 22

8.1. Procedure 22

8.2. Results & discussion 23

9. General discussion 24

10. References 28

List of Figures

Figure 1. 4

Figure 2. 6

Figure 3. 7

Figure 4. 9

Figure 5. 11

Figure 6. 13

Figure 7. 15

Figure 8. 17

Figure 9. 18

Figure 10. 19

Figure 11. 21

Figure 12. 23

About this Master's Thesis

Rights statement
  • Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.
Subfield / Discipline
  • English
Research Field
Committee Chair / Thesis Advisor
Committee Members
Last modified Preview image embargoed

Primary PDF

Supplemental Files