Journal of Comparative Psychology最新文献

The Journal of Comparative Psychology (JCP) is the flagship APA journal dedicated to understanding psychological processes from a comparative perspective. Traditionally, "comparative" has meant comparison across species. However, "comparative" means more than just assessing as many species as possible or relating species to each other. I also think of the importance of a "comparative psychology" perspective in two other ways that should be reflected in the journal's publications. I would like to outline a few important points about how I view the mission of JCP, and how my term as chief editor will address some of the major issues that exist for the journal and for the field of comparative psychology more broadly. Preregistration, replication, and the review process are highlighted. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Executive function (EF) involves several abilities often correlated with success in various aspects of human life. Similar skills could also be advantageous to nonhumans, but few studies have effectively examined the extent of their EF abilities. Studies have also examined what experiences might strengthen/weaken human EF; might specific experiences also affect nonhuman EF? One type of EF often tested in both humans and nonhumans involves a delay of gratification-the ability to forgo an immediate reward to gain one either better in quality or quantity. We compared how Grey parrots (Psittacus erithacus) with somewhat different experimental histories performed when required to wait for more food-a difficult task for avian species. One laboratory-raised parrot, Griffin, had previously succeeded when asked to wait for a better reward and on other tasks purportedly involving some level of EF skills but failed to wait for a larger reward. After succeeding on a task designed to improve impulse control, he consistently waited for a larger reward, more nuts, for up to 15 min-far longer than most avian species tested. Two other parrots, Pepper and Franco, companion animals, had had no experience with delayed gratification tasks, but were as successful as Griffin on other EF-related studies in which they participated. These birds, with different histories than Griffin, also waited for more food for longer periods than most other birds, though not as consistently as Griffin. We suggest that specific types of experiences may strengthen EF in Grey parrots. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Engaging executive functions provides an individual with the means to engage in cognitive control by adjusting to the environment and processing information in a way that leads to optimal outcomes. There are some claims that explicit training on certain executive functioning abilities provides benefits beyond the training tasks, but other studies indicate that this may not be true or may be limited based on age and other factors. This same mixed pattern has been reported with nonhuman species, where training or even experience in one specific area, like inhibition, sometimes leads to positive transfer in new but similar tasks that presumably also require executive functions. Pepperberg and Hartsfield (2024) sought to determine whether experience in previous tasks that required different executive functions impacted how well three African grey parrots: Griffin, Pepper, and Franco could perform in a new assessment of delayed gratification. Griffin showed a clear and consistent capacity to wait through a delay for a quantitatively better reward. This suggested that the previous experience with the tokens aided improvement in the quantitative delay of gratification task with food items as the options to choose between. The other two parrots, Pepper and Franco, never completed the intended sequence of phases in their study. Unfortunately, the testing conditions dictated by COVID restrictions were such that these two subjects appeared to exhibit stress in doing the task, and so no further testing was conducted with them. This article is an example of what can happen when two intelligent species (people and parrots) are put in difficult circumstances (a global pandemic unlike anything any of us has ever been through), and yet both species attempted to continue to engage in science. The effects of COVID-19 will remain an integral factor in comparative psychology for some time to come, and I suspect there are many other half-completed experiments that suffered because of the pandemic. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Primate facial musculature enables a wide variety of movements during bouts of communication, but how these movements contribute to signal construction and repertoire size is unclear. The facial mobility hypothesis suggests that morphological constraints shape the evolution of facial repertoires: species with higher facial mobility will produce larger and more complex repertoires. In contrast, the socio-ecological complexity hypothesis suggests that social needs shape the evolution of facial repertoires: as social complexity increases, so does communicative repertoire size. We tested these two hypotheses by comparing chimpanzees (Pan troglodytes) and gibbons (family Hylobatidae), two distantly related apes who vary in their facial mobility and social organization. While gibbons have higher facial mobility than chimpanzees, chimpanzees live in more complex social groups than gibbons. We compared the morphology and complexity of facial repertoires for both apes using Facial Action Coding Systems designed for chimpanzees and gibbons. Our comparisons were made at the level of individual muscle movements (action units [AUs]) and the level of muscle movement combinations (AU combinations). Our results show that the chimpanzee facial signaling repertoire was larger and more complex than gibbons, consistent with the socio-ecological complexity hypothesis. On average, chimpanzees produced AU combinations consisting of more morphologically distinct AUs than gibbons. Moreover, chimpanzees also produced more morphologically distinct AU combinations than gibbons, even when focusing exclusively on AUs present in both apes. Therefore, our results suggest that socio-ecological factors were more important than anatomical ones to the evolution of facial signaling repertoires in chimpanzees and gibbons. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A defining feature of most primates is a hand with five fingers. Spider monkeys are an exception because they have four fingers and no thumb. Despite the prevalence of reach-to-grasp research in primates, it is not known how the lack of a thumb affects reaching and grasping in spider monkeys. Drawing on patterns that have been well described in human adults, human infants, and other nonhuman primates, this study characterized prehension in Colombian spider monkeys (Ateles fusciceps rufiventris). Monkeys reached for two differently sized food objects and reaches were digitized offline for two-dimensional kinematic analysis. Grasp strategy was coded from video as preshaped when the hand was adjusted to grasp the food before contact, or not preshaped when the hand was adjusted to grasp the food after contact. Monkeys exhibited variability in reach smoothness that contrasted with the typical pattern seen in other adult primates and instead resembled the pattern observed in human infants. Monkeys anticipated the object to be grasped approximately half of the time. Reaches where the hand was preshaped to the object were smoother than reaches where the hand was adjusted to grasp after object contact. For the small object, reaches with preshaping were straighter than reaches without preshaping. Results are the first evidence of kinematic signatures for reach-to-grasp actions in spider monkeys. (PsycInfo Database Record (c) 2024 APA, all rights reserved).