Limits...
Chimpanzees (Pan troglodytes) flexibly adjust their behaviour in order to maximize payoffs, not to conform to majorities.

Van Leeuwen EJ, Cronin KA, Schütte S, Call J, Haun DB - PLoS ONE (2013)

Bottom Line: Yet, sometimes their conservative nature seems to hamper the flexible adoption of superior alternatives, even to the extent that they persist in using entirely ineffective strategies.In this study, we investigated chimpanzees' behavioural flexibility in two different conditions under which social animals have been predicted to abandon personal preferences and adopt alternative strategies: i) under influence of majority demonstrations (i.e. conformity), and ii) in the presence of superior reward contingencies (i.e. maximizing payoffs).Studying captive (n=16) and semi-wild (n=12) chimpanzees in two complementary exchange paradigms, we found that chimpanzees did not abandon their behaviour in order to match the majority, but instead remained faithful to their first-learned strategy (Study 1a and 1b).

View Article: PubMed Central - PubMed

Affiliation: Max Planck Research Group for Comparative Cognitive Anthropology, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands.

ABSTRACT
Chimpanzees have been shown to be adept learners, both individually and socially. Yet, sometimes their conservative nature seems to hamper the flexible adoption of superior alternatives, even to the extent that they persist in using entirely ineffective strategies. In this study, we investigated chimpanzees' behavioural flexibility in two different conditions under which social animals have been predicted to abandon personal preferences and adopt alternative strategies: i) under influence of majority demonstrations (i.e. conformity), and ii) in the presence of superior reward contingencies (i.e. maximizing payoffs). Unlike previous nonhuman primate studies, this study disentangled the concept of conformity from the tendency to maintain one's first-learned strategy. Studying captive (n=16) and semi-wild (n=12) chimpanzees in two complementary exchange paradigms, we found that chimpanzees did not abandon their behaviour in order to match the majority, but instead remained faithful to their first-learned strategy (Study 1a and 1b). However, the chimpanzees' fidelity to their first-learned strategy was overridden by an experimental upgrade of the profitability of the alternative strategy (Study 2). We interpret our observations in terms of chimpanzees' relative weighing of behavioural options as a function of situation-specific trade-offs. More specifically, contrary to previous findings, chimpanzees in our study abandoned their familiar behaviour to maximize payoffs, but not to conform to a majority.

Show MeSH
Mean (± s.e.m.) percentage by which the minority chimpanzees of Study 1 (n=5) observed majority strategy demonstrations, both in absolute frequencies (#) and in number of unique demonstrators (d), supplemented with the median percentages (with the lower and upper error hinge representing the first and third quartile, respectively) by which the minority chimpanzees chose to use the majority strategy per day (Exp. 1a: mean choices per individual per day = 39.9 token exchanges, range 38-103; Exp. 1b: mean choices per individual per day = 11.4 exchanges at the vending machines, range 7-23).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3842352&req=5

pone-0080945-g003: Mean (± s.e.m.) percentage by which the minority chimpanzees of Study 1 (n=5) observed majority strategy demonstrations, both in absolute frequencies (#) and in number of unique demonstrators (d), supplemented with the median percentages (with the lower and upper error hinge representing the first and third quartile, respectively) by which the minority chimpanzees chose to use the majority strategy per day (Exp. 1a: mean choices per individual per day = 39.9 token exchanges, range 38-103; Exp. 1b: mean choices per individual per day = 11.4 exchanges at the vending machines, range 7-23).

Mentions: Focusing in on the chimpanzees in the minorities, we found no evidence for conformity in either chimpanzee population. While the perception records indicated that minority chimpanzees more often observed chimpanzees using the majority strategy compared to the minority strategy, both in absolute frequency (regardless of which individual was exchanging) and in the number of unique individuals (see Figure 3), they remained faithful to their trained strategy with high fidelity (W=2.06, n=5, p=0.039; Figure 3), both in Study 1a (n=2, median = 99.1%, range = 67.9 - 100%, token exchanges per individual per day M = 38.7) and Study 1b (n=3, median = 100%, range = 33.3 - 100%, free exchanges at the vending machines per individual per day M = 8.7). See Table S2 for an overview of all token and vending machine exchanges of the minority chimpanzees in Study 1a and 1b.


Chimpanzees (Pan troglodytes) flexibly adjust their behaviour in order to maximize payoffs, not to conform to majorities.

Van Leeuwen EJ, Cronin KA, Schütte S, Call J, Haun DB - PLoS ONE (2013)

Mean (± s.e.m.) percentage by which the minority chimpanzees of Study 1 (n=5) observed majority strategy demonstrations, both in absolute frequencies (#) and in number of unique demonstrators (d), supplemented with the median percentages (with the lower and upper error hinge representing the first and third quartile, respectively) by which the minority chimpanzees chose to use the majority strategy per day (Exp. 1a: mean choices per individual per day = 39.9 token exchanges, range 38-103; Exp. 1b: mean choices per individual per day = 11.4 exchanges at the vending machines, range 7-23).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3842352&req=5

pone-0080945-g003: Mean (± s.e.m.) percentage by which the minority chimpanzees of Study 1 (n=5) observed majority strategy demonstrations, both in absolute frequencies (#) and in number of unique demonstrators (d), supplemented with the median percentages (with the lower and upper error hinge representing the first and third quartile, respectively) by which the minority chimpanzees chose to use the majority strategy per day (Exp. 1a: mean choices per individual per day = 39.9 token exchanges, range 38-103; Exp. 1b: mean choices per individual per day = 11.4 exchanges at the vending machines, range 7-23).
Mentions: Focusing in on the chimpanzees in the minorities, we found no evidence for conformity in either chimpanzee population. While the perception records indicated that minority chimpanzees more often observed chimpanzees using the majority strategy compared to the minority strategy, both in absolute frequency (regardless of which individual was exchanging) and in the number of unique individuals (see Figure 3), they remained faithful to their trained strategy with high fidelity (W=2.06, n=5, p=0.039; Figure 3), both in Study 1a (n=2, median = 99.1%, range = 67.9 - 100%, token exchanges per individual per day M = 38.7) and Study 1b (n=3, median = 100%, range = 33.3 - 100%, free exchanges at the vending machines per individual per day M = 8.7). See Table S2 for an overview of all token and vending machine exchanges of the minority chimpanzees in Study 1a and 1b.

Bottom Line: Yet, sometimes their conservative nature seems to hamper the flexible adoption of superior alternatives, even to the extent that they persist in using entirely ineffective strategies.In this study, we investigated chimpanzees' behavioural flexibility in two different conditions under which social animals have been predicted to abandon personal preferences and adopt alternative strategies: i) under influence of majority demonstrations (i.e. conformity), and ii) in the presence of superior reward contingencies (i.e. maximizing payoffs).Studying captive (n=16) and semi-wild (n=12) chimpanzees in two complementary exchange paradigms, we found that chimpanzees did not abandon their behaviour in order to match the majority, but instead remained faithful to their first-learned strategy (Study 1a and 1b).

View Article: PubMed Central - PubMed

Affiliation: Max Planck Research Group for Comparative Cognitive Anthropology, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands.

ABSTRACT
Chimpanzees have been shown to be adept learners, both individually and socially. Yet, sometimes their conservative nature seems to hamper the flexible adoption of superior alternatives, even to the extent that they persist in using entirely ineffective strategies. In this study, we investigated chimpanzees' behavioural flexibility in two different conditions under which social animals have been predicted to abandon personal preferences and adopt alternative strategies: i) under influence of majority demonstrations (i.e. conformity), and ii) in the presence of superior reward contingencies (i.e. maximizing payoffs). Unlike previous nonhuman primate studies, this study disentangled the concept of conformity from the tendency to maintain one's first-learned strategy. Studying captive (n=16) and semi-wild (n=12) chimpanzees in two complementary exchange paradigms, we found that chimpanzees did not abandon their behaviour in order to match the majority, but instead remained faithful to their first-learned strategy (Study 1a and 1b). However, the chimpanzees' fidelity to their first-learned strategy was overridden by an experimental upgrade of the profitability of the alternative strategy (Study 2). We interpret our observations in terms of chimpanzees' relative weighing of behavioural options as a function of situation-specific trade-offs. More specifically, contrary to previous findings, chimpanzees in our study abandoned their familiar behaviour to maximize payoffs, but not to conform to a majority.

Show MeSH