Wolves and dogs recruit human partners in the cooperative string-pulling task

Development of a Marmoset Apparatus for Automated Pulling (MarmoAAP) to Study Cooperative Behaviors

In recent years, the field of neuroscience has increasingly recognized the importance of studying animal behaviors in naturalistic environments to gain deeper insights into ethologically relevant behavioral processes and neural mechanisms. The common marmoset (Callithrix jacchus), due to its small size, prosocial nature, and genetic proximity to humans, has emerged as a pivotal model toward this effort. However, traditional research methodologies often fail to fully capture the nuances of marmoset social interactions and cooperative behaviors. To address this critical gap, we developed the Marmoset Apparatus for Automated Pulling (MarmoAAP), a novel behavioral apparatus designed for studying cooperative behaviors in common marmosets. MarmoAAP addresses the limitations of traditional behavioral research methods by enabling high-throughput, detailed behavior outputs that can be integrated with video and audio recordings, allowing for more nuanced and comprehensive analyses even in a naturalistic setting. We also highlight the flexibility of MarmoAAP in task parameter manipulation which accommodates a wide range of behaviors and individual animal capabilities. Furthermore, MarmoAAP provides a platform to perform investigations of neural activity underlying naturalistic social behaviors. MarmoAAP is a versatile and robust tool for advancing our understanding of primate behavior and related cognitive processes. This new apparatus bridges the gap between ethologically relevant animal behavior studies and neural investigations, paving the way for future research in cognitive and social neuroscience using marmosets as a model organism.

Some dogs can find the payoff-dominant outcome in the Assurance game

Studies on coordination often present animals with the choice of either cooperating or remaining inactive; however, in nature, animals may also choose to act alone. This can be modeled with the Assurance game, an economic game that has recently been used to explore decision-making in primates. We investigated whether dyads of pet dogs coordinate in the Assurance game. Pairs were presented with two alternatives: they could individually solve an apparatus baited with a low-value reward (Hare) or they could coordinate to solve a cooperative apparatus baited with a high-value reward for each dog (Stag). All individuals matched their partner's choices, but after controlling for side bias, only four out of eleven dyads consistently coordinated on the payoff-dominant strategy (Stag-Stag). Thus, some dogs are capable of finding coordinated outcomes, as do primates, at least when their partner's actions are visible and coordination results in the biggest payoff for both individuals.

Are domesticated animals dumber than their wild relatives? A comprehensive review on the domestication effects on animal cognitive performance

Animal domestication leads to diverse behavioral, physiological, and neurocognitive changes in domesticated species compared to their wild relatives. However, the widely held belief that domesticated species are inherently less "intelligent" (i.e., have lower cognitive performance) than their wild counterparts requires further investigation. To investigate potential cognitive disparities, we undertook a thorough review of 88 studies comparing the cognitive performance of domesticated and wild animals. Approximately 30% of these studies showed superior cognitive abilities in wild animals, while another 30% highlighted superior cognitive abilities in domesticated animals. The remaining 40% of studies found similar cognitive performance between the two groups. Therefore, the question regarding the presumed intelligence of wild animals and the diminished cognitive ability of domesticated animals remains unresolved. We discuss important factors/limitations for interpreting past and future research, including environmental influences, diverse objectives of domestication (such as breed development), developmental windows, and methodological issues impacting cognitive comparisons. Rather than perceiving these limitations as constraints, future researchers should embrace them as opportunities to expand our understanding of the complex relationship between domestication and animal cognition.

Factors Contributing to Successful Spontaneous Dog-Human Cooperation

Dogs' ability to cooperate with humans is widely acknowledged, but the factors influencing their spontaneous cooperative tendencies are largely unknown. We investigated whether breed function, training experience, and owner-reported social motivation level contribute to spontaneous dog-owner cooperation. Family dogs (N = 100) of three breed groups (non-working dogs, cooperative/independent working breeds) with various training experiences were tested in an 'out-of-reach' task with their owners as their partners, who never directly asked for help during the test. We measured dogs' behaviour along three main components of successful cooperation: paying attention, understanding the problem, and willingness to cooperate. Breed groups had no significant effect on dogs' behaviour. No factor was associated with the behavioural variables related to not understanding the task. Dogs with high training levels and high social motivation showed more attention-related behaviours and were more likely to help the owner (training level and social motivation were not correlated with each other). Our results highlight the importance of training experience and social motivation in dogs' attentiveness and spontaneous cooperativity. This also points to the need for careful sample balancing and experimental procedures that do not rely on specific trained skills.

Cooperation increases bottlenose dolphins' (Tursiops truncatus) social affiliation

Dolphins live in a fission-fusion society, where strong social bonds and alliances can last for decades. However, the mechanism that allows dolphins to form such strong social bonds is still unclear. Here, we hypothesized the existence of a positive feedback mechanism in which social affiliation promotes dolphins' cooperation, which in turn promotes their social affiliation. To test it, we stimulated the cooperation of the 11 dolphins studied by providing a cooperative enrichment tool based on a rope-pulling task to access a resource. Then we measured the social affiliation [simple ratio index (SRI)] of each possible pair of dolphins and evaluated whether it increased after cooperation. We also evaluated whether, before cooperation, pairs that cooperated had a higher SRI than those that did not cooperate. Our findings showed that the 11 cooperating pairs had significantly stronger social affiliation before cooperation than the 15 non-cooperating pairs. Furthermore, cooperating pairs significantly increased their social affiliation after cooperation, while non-cooperating pairs did not. As a result, our findings provide support to our hypothesis, and suggest that the previous social affiliation between dolphins facilitates cooperation, which in turn promotes their social affiliation.

Dogs take into account the actions of a human partner in a cooperative task

Humans stand out for their capacity to flexibly cooperate, possibly because they understand their partners' role. Researchers have explored if such understanding is unique to humans by assessing whether non-human species wait to manipulate a cooperative apparatus until a delayed partner arrives. If animals do wait, then it is assumed that they recognize the need for a partner. However, success in these tasks may be the result of social facilitation, while failure may be due to poor inhibitory control. Moreover, this approach does not test if animals take their partners' actions into account. Here we trained dogs to press a button simultaneously with their human partner. Afterwards, we tested them in several conditions to disentangle which elements of their partner's behaviour they take into account. Dogs waited to press the button until the delayed partner arrived, the button was available to the partner and the partner acted (pressed the button). We found no relationship between inhibitory control and success. We conclude that dogs are not merely reacting to the presence of their human partners, but are also taking their actions into account when coordinating with them.

Wolves and dogs fail to form reputations of humans after indirect and direct experience in a food-giving situation

Reputation is a key component in social interactions of group-living animals and appears to play a role in the establishment of cooperation. Animals can form reputations of individuals by directly interacting with them or by observing them interact with a third party, i.e., eavesdropping. Previous research has focused on whether dogs (Canis lupus familiaris) can eavesdrop on humans because of their ability to cooperate with humans, however the results are mixed and if they can eavesdrop, it is unknown whether this ability evolved during the domestication process or whether it was inherited from their ancestor, wolves (Canis lupus). Our study investigated whether equally hand-raised, pack-living dogs and wolves can form reputations of humans in a food-giving situation through indirect and/or direct experience. The experimental procedure comprised three parts: baseline (to test whether the subject preferred a person prior to the experiment), observation and testing. In the observation phase, the subject observed two humans interact with a dog demonstrator-one acted generously and fed the dog, and the other acted selfishly and refused to feed the dog. The subject could then choose which person to approach in the test phase. In the following experience phase, the animals interacted directly with the same two humans who behaved either in a generous or selfish manner. Then, they were again given a choice whom to approach. We found that dogs and wolves, at the group level, did not differentiate between a generous or selfish partner after indirect or direct experience, but wolves were more attentive towards the generous person during the observation phase and some dogs and wolves did prefer the generous partner, at least after indirect and direct experience was combined. Our study suggests that reputation formation may be more difficult than expected for animals and we emphasise the importance of context when studying reputation formation in animals.

Investigating Indirect and Direct Reputation Formation in Asian Elephants (Elephas maximus)

Reputation is a key component in social interactions of group-living animals and appears to play a role in the establishment of cooperation. Animals can form a reputation of an individual by directly interacting with them or by observing them interact with a third party, i.e., eavesdropping. Elephants are an interesting taxon in which to investigate eavesdropping as they are highly cooperative, large-brained, long-lived terrestrial mammals with a complex social organisation. The aim of this study was to investigate whether captive Asian elephants (Elephas maximus) could form reputations of humans through indirect and/or direct experience in two different paradigms: (1) a cooperative string-pulling task and (2) a scenario requiring begging. Fourteen captive Asian elephants in Thailand participated in an experimental procedure that consisted of three parts: baseline, observation, and testing. In the observation phase, the subject saw a conspecific interact with two people-one cooperative/generous and one non-cooperative/selfish. The observer could then choose which person to approach in the test phase. The elephants were tested in a second session 2-5 days later. We found no support for the hypothesis that elephants can form reputations of humans through indirect or direct experience, but these results may be due to challenges with experimental design rather than a lack of capacity. We discuss how the results may be due to a potential lack of ecological validity in this study and the difficulty of assessing motivation and attentiveness in elephants. Furthermore, we highlight the importance of designing future experiments that account for the elephants' use of multimodal sensory information in their decision-making.

Context-Specific Arousal During Resting in Wolves and Dogs: Effects of Domestication?

Due to domestication, dogs differ from wolves in the way they respond to their environment, including to humans. Selection for tameness and the associated changes to the autonomic nervous system (ANS) regulation have been proposed as the primary mechanisms of domestication. To test this idea, we compared two low-arousal states in equally raised and kept wolves and dogs: resting, a state close to being asleep, and inactive wakefulness, which together take up an important part in the time budgets of wolves and dogs. We measured arousal via cardiac output in three conditions: alone, with a familiar human partner, or with pack members (i.e., conspecifics). Specifically, we compared heart rate (HR) and heart rate variability (HRV) of six wolves and seven dogs. As patterns of resting can vary adaptively, even between closely related species, we predicted that dogs would be generally more aroused than wolves, because living with humans may come with less predictable contexts than living with conspecifics; hence, dogs would need to be responsive at all times. Furthermore, we predicted that due to the effects of domestication, emotional social support by familiar people would reduce arousal more in dogs than in equally human-socialized wolves, leading to more relaxed dogs than wolves when away from the pack. Overall, we found a clear effect of the interactions between species (i.e., wolf versus dog), arousal state (i.e., resting or awake inactive) and test conditions, on both HR and HRV. Wolves and dogs were more aroused when alone (i.e., higher HR and lower HRV) than when in the presence of conspecifics or a familiar human partner. Dogs were more relaxed than wolves when at rest and close to a familiar human but this difference disappeared when awake. In conclusion, instead of the expected distinct overall differences between wolves and dogs in ANS regulation, we rather found subtle context-specific responses, suggesting that such details are important in understanding the domestication process.

How animals collaborate: Underlying proximate mechanisms

Collaboration or social interactions in which two or more individuals coordinate their behavior to produce outcomes from which both individuals benefit are common in nature. Individuals from many species hunt together, defend their territory, and form coalitions in intragroup competition. However, we still know very little about the proximate mechanisms underlying these behaviors. Recent theories of human cognitive evolution have emphasized the role collaboration may have played in the selection of socio-cognitive skills. It has been argued that the capacity to form shared goals and joint intentions with others, is what allows humans to collaborate so flexibly and efficiently. Although there is no evidence that nonhuman animals are capable of shared intentionality, there is conceivably a wide range of proximate mechanisms that support forms of, potentially flexible, collaboration in other species. We review the experimental literature with the aim of evaluating what we know about how other species achieve collaboration; with a particular focus on chimpanzees. We structure the review with a new categorization of collaborative behavior that focuses on whether individuals intentionally coordinate actions with others. We conclude that for a wider comparative perspective we need more data from other species but the findings so far suggest that chimpanzees, and possibly other great apes, are capable of understanding the causal role of a partner in collaboration. This article is categorized under: Cognitive Biology > Evolutionary Roots of Cognition Psychology > Comparative Psychology.