Prosocial behaviors have been considered a hallmark of humans in the past. However, accumulating experimental data in comparative cognitive science have revealed that nonhuman animals also show prosocial behaviors. Nevertheless, its evolutionary path has remained unclear despite a great deal of recent research effort. In this paper, I first review experimental studies on prosocial behaviors in nonhuman primates, by focusing on the influences of request behavior and social closeness. Then, I evaluate some factors that have been thought to play an important role in facilitating the convergent evolution of prosocial behaviors (inequity aversion, interdependence, tolerance) based on experimental data. I finally propose some possible future studies to explore the evolutionary path of prosocial behaviors, by referring to the previously discussed psychological mechanism that seems to support nonhuman primates’ prosocial behaviors (Yamamoto & Takimoto, 2012).
The science of emotion is in a crisis: despite an enormous literature studying emotion from the perspectives of psychology and neuroscience, there is little agreement on any theory of emotion. The most acute problem is that our commonsense concept of "emotion" essentially involves conscious experience, whereas the scientific concept should not. I suggest that this state of affairs is, however, no different than in any other domain of cognitive psychology or cognitive neuroscience. Numerous examples show the need for a scientific concept of emotion. Both psychological and neurological data require such a concept in order to make sense of the data. I argue that (a) we cannot dispense with a scientific concept of "emotion"; and (b) such a concept needs to be grounded in broad data across a range of species; and (c) we need to begin formulating specific criteria for its application. In this paper I begin by outlining what the problem is, give some examples from my own research, and conclude with a framework for thinking about emotions that gives them scientific purchase.
Prospective memory requires forming an intention that cannot be completed at the present time, remembering that intention, and then recognizing the appropriate time to execute it. We review recent work in our laboratory that has revealed prospective memory-like patterns of performance in nonhuman primates. Rhesus monkeys and capuchin monkeys were given computerized tasks in which the monkeys either had to remember a future response they could not make immediately, or they sometimes saw a particular stimulus during an ongoing task they had to remember to later indicate seeing or not seeing. Most monkeys succeeded on these tasks and even anticipated the necessary responses. Chimpanzees also showed evidence of prospective memory. They appeared to form intentions about less valuable food items that they did not want immediately but would want later, and they responded at a later time when it was possible to obtain those items. Even when the response option was embedded within an ongoing task, the chimpanzees still showed some success in remembering to carry out the prospective intention. This research indicates that nonhuman primates form intentions for future responses, maintain those intentions during a delay, and execute them at an appropriate time.
While the evolution of cooperative behaviors has generated an intense debate among evolutionists and animal behaviorists, the proximate mechanisms underlying cooperative relationships have received much less attention. In recent years, it has become clear that an understanding of proximate causation of cooperation is needed in order to obtain a more balanced and complete picture of the phenomenon. The proximate cause of cooperation refers to the immediate situation that triggers behavior, and the role of learning, memory, physiology, and neural processes. Since from an evolutionary point of view cooperative relationships are maintained because of the subsequent benefits they bring, there has been the tendency to erroneously assume that they are also motivated by their future benefits. This assumption would imply that animals engage in social interactions in order to gain future benefits, or that they are able to remember the services given by another individual in order to offer a service in return at a later date. While this "rational" calculation offers a possible explanation, it is currently unclear whether or not some animal species have these cognitive capacities. Here I will argue that, while complex cognitive mechanisms may be present in some species, less cognitively demanding mechanisms, based on emotions, could be at the basis of the flexibility needed to form complex, enduring cooperative relationships in both human and non-human animals.
This paper considers methodological problems in animal metacognition studies. After summarizing a variety of experimental designs to study animal metacognition, we review recent literature that were not included in Fujita (2010)'s more comprehensive review. We then examined Carruthers (2008; Carruthers and Rithie 2012)' skeptic argument against animal metacognition. He argued that no experiments thus far successfully exclude the possibility that animals, as well as human infants, elicit "metacognitive" responses without explicitly and consciously monitoring internal representations. We argued that newly developed experimental paradigms to study explicit memory processes could be a key to reject Caruuthers' skeptic argument and thus facilitate understanding how we access to the internal representations.