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Insights into Intraspecies Variation in Primate Prosocial Behavior: Capuchins (Cebus apella) Fail to Show Prosociality on a Touchscreen Task.

Drayton LA, Santos LR - Behav Sci (Basel) (2014)

Bottom Line: In contrast to previous studies, we found that capuchins as a group did not prosocially deliver food to a partner.We also compared individuals' performance in the current study with their performance in a previously published prosociality study.We conclude by discussing how continuing to explore intraspecies variation in performance on prosocial tasks may help inform debates regarding the existence of other-regarding preferences in nonhuman species.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Yale University, 2 Hillhouse Avenue, New Haven, CT 06511, USA; E-Mail: lindsey.drayton@gmail.com.

ABSTRACT
Over the past decade, many researchers have used food donation tasks to test whether nonhuman primates show human-like patterns of prosocial behavior in experimental settings. Although these tasks are elegant in their simplicity, performance within and across species is difficult to explain under a unified theoretical framework. Here, we attempt to better understand variation in prosociality by examining the circumstances that promote and hinder the expression of prosocial preferences. To this end, we tested whether capuchin monkeys (Cebus apella)-a species that has previously demonstrated prosocial preferences-would behave prosocially using a novel touchscreen task. In contrast to previous studies, we found that capuchins as a group did not prosocially deliver food to a partner. Importantly however, data from control conditions revealed that subjects demonstrated limited understanding of the reward contingencies of the task. We also compared individuals' performance in the current study with their performance in a previously published prosociality study. We conclude by discussing how continuing to explore intraspecies variation in performance on prosocial tasks may help inform debates regarding the existence of other-regarding preferences in nonhuman species.

No MeSH data available.


Related in: MedlinePlus

Mean percent (+SE) of prosocial choices by actors in the three conditions. Asterisks denote when actors’ behavior was significantly different from chance.
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behavsci-04-00087-f004: Mean percent (+SE) of prosocial choices by actors in the three conditions. Asterisks denote when actors’ behavior was significantly different from chance.

Mentions: Turning to the two pairs of stimuli that offered a prosocial and a selfish option (1/1 vs. 1/0 and 0/1 vs. 0/0), we compared the number of times in each condition that actors as a group selected the prosocial stimulus (1/1 and 0/1, respectively) to chance levels, again using binomial tests. When offered the choice between 1/1 and 1/0, actors chose the prosocial option on 54% of all trials. In no condition did actors as a group choose the prosocial stimulus at levels significantly different from chance (N = 96 total observations across all monkeys, all ps > 0.35; Figure 4). A Friedman’s test revealed that, contrary to our predictions, actors did not select the prosocial stimulus at different rates across the different test conditions (χ2(2) = 0.143, p = 0.944). Nevertheless, to test our directional hypotheses we conducted planned comparisons between empty control sessions and selfish control sessions and between the empty control sessions and prosocial test sessions using two-tailed Wilcoxon Signed-Rank tests with a Bonferroni adjusted alpha level of 0.025 per test. We found no difference in the group’s behavior in empty control sessions and selfish control sessions (Z = −0.736, p = 0.5) or in empty control sessions and prosocial test sessions (Z = 0, p > 0.999).


Insights into Intraspecies Variation in Primate Prosocial Behavior: Capuchins (Cebus apella) Fail to Show Prosociality on a Touchscreen Task.

Drayton LA, Santos LR - Behav Sci (Basel) (2014)

Mean percent (+SE) of prosocial choices by actors in the three conditions. Asterisks denote when actors’ behavior was significantly different from chance.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4219244&req=5

behavsci-04-00087-f004: Mean percent (+SE) of prosocial choices by actors in the three conditions. Asterisks denote when actors’ behavior was significantly different from chance.
Mentions: Turning to the two pairs of stimuli that offered a prosocial and a selfish option (1/1 vs. 1/0 and 0/1 vs. 0/0), we compared the number of times in each condition that actors as a group selected the prosocial stimulus (1/1 and 0/1, respectively) to chance levels, again using binomial tests. When offered the choice between 1/1 and 1/0, actors chose the prosocial option on 54% of all trials. In no condition did actors as a group choose the prosocial stimulus at levels significantly different from chance (N = 96 total observations across all monkeys, all ps > 0.35; Figure 4). A Friedman’s test revealed that, contrary to our predictions, actors did not select the prosocial stimulus at different rates across the different test conditions (χ2(2) = 0.143, p = 0.944). Nevertheless, to test our directional hypotheses we conducted planned comparisons between empty control sessions and selfish control sessions and between the empty control sessions and prosocial test sessions using two-tailed Wilcoxon Signed-Rank tests with a Bonferroni adjusted alpha level of 0.025 per test. We found no difference in the group’s behavior in empty control sessions and selfish control sessions (Z = −0.736, p = 0.5) or in empty control sessions and prosocial test sessions (Z = 0, p > 0.999).

Bottom Line: In contrast to previous studies, we found that capuchins as a group did not prosocially deliver food to a partner.We also compared individuals' performance in the current study with their performance in a previously published prosociality study.We conclude by discussing how continuing to explore intraspecies variation in performance on prosocial tasks may help inform debates regarding the existence of other-regarding preferences in nonhuman species.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Yale University, 2 Hillhouse Avenue, New Haven, CT 06511, USA; E-Mail: lindsey.drayton@gmail.com.

ABSTRACT
Over the past decade, many researchers have used food donation tasks to test whether nonhuman primates show human-like patterns of prosocial behavior in experimental settings. Although these tasks are elegant in their simplicity, performance within and across species is difficult to explain under a unified theoretical framework. Here, we attempt to better understand variation in prosociality by examining the circumstances that promote and hinder the expression of prosocial preferences. To this end, we tested whether capuchin monkeys (Cebus apella)-a species that has previously demonstrated prosocial preferences-would behave prosocially using a novel touchscreen task. In contrast to previous studies, we found that capuchins as a group did not prosocially deliver food to a partner. Importantly however, data from control conditions revealed that subjects demonstrated limited understanding of the reward contingencies of the task. We also compared individuals' performance in the current study with their performance in a previously published prosociality study. We conclude by discussing how continuing to explore intraspecies variation in performance on prosocial tasks may help inform debates regarding the existence of other-regarding preferences in nonhuman species.

No MeSH data available.


Related in: MedlinePlus