Journal of Comparative Psychology最新文献

When making decisions, humans often strive to uphold objective, absolute standards, such as about what is small versus large, blue versus purple, or unfair versus fair, suggesting that our judgments should not be swayed by extraneous factors such as the sequence or frequency of events to be judged. Yet in previous research, when some items (e.g., threatening faces) became less frequent, humans responded by expanding their concept (of "threatening") to include more ambiguous stimuli. We assessed the origins of this perceptual frequency bias by testing 25 capuchins, seven rhesus monkeys, and 102 humans on a computer task in which they had to classify one circle at a time (pulled from a continuum of 50 circle sizes) as either small or large. Small and large circles initially appeared with equal probability but over time small circles either became less frequent, more frequent, or did not change in frequency. All three species showed changes in judgment, but contrary to predictions, they contracted, rather than expanded, their size judgments of the less frequent category. In other words, when small circles became rare, participants were more likely to judge ambiguous circles sizes as large (and vice versa). This may have been due to the immediate explicit feedback, as has recently been found in humans, and we consider possible mechanisms driving our participants' responses. These results suggest that humans' difficulties in maintaining absolute standards are shared with other animals. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A growing body of research demonstrates that humans can accurately perceive the emotional states of animals solely by listening to their calls, highlighting shared evolutionary ancestry. Yet, the cognitive and perceptual mechanisms underlying heterospecific emotion perception have remained open to investigation. One hypothesis is that humans rely on simple acoustic heuristics to make such judgments, for example, perceiving higher-pitched calls as reflecting heightened emotional arousal (the "pitch rule"). This could lead to accurate judgments of emotion since in most mammals, as in humans, vocal fundamental frequency (the acoustic determinant of the pitch percept) does objectively correlate with emotional arousal. In the present study, we used digital pitch manipulation to create pairs of animal calls that were perceptually identical except for pitch, and we measured human perceptions of the caller's emotional arousal using an online survey. Calls of six phylogenetically diverse species were included as stimuli. Participants attributed slightly but statistically significantly higher arousal to higher-pitched versions of the same calls. Variation in application of the pitch rule across species was not well explained by familiarity, and prior experience with cats did not significantly predict sensitivity to pitch in cat vocalizations. Cross-species variation also did not align with phylogenetic distance from humans, or the hypothetical usefulness of pitch for making accurate judgments. Thus, the pitch rule may be a "mammalomorphic" heuristic leading to accurate emotion judgments in some taxa and call types and erroneous judgments in others, depending in part on phylogenetic distance and the mechanisms of call production. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Goodyear and Kamil (2004) assessed the ability of Clark's nutcrackers to find buried food based on a cross-shaped array of landmarks at different distances from the goal. Their findings suggested that proximal landmarks overshadowed learning about distal landmarks, and this was attenuated when assessing the effect of distal landmarks on learning about proximal landmarks. In this study, we aimed to replicate their findings in human spatial navigation by using a virtual environment. Three groups of participants were trained in an open environment featuring orientation cues, and they had to find a hidden goal with reference to four landmarks that were arranged in the shape of a cross and placed at different distances from the goal. Two of the four landmark distances were common across all three groups to allow a comparison of the extent of overshadowing under comparable conditions. Following training, all participants were tested with each of the four landmarks individually. Consistent with the results in birds, we observed better performance in the groups with more distal landmarks, suggesting that overshadowing was greater in the groups with closer landmarks and thus dependent on the spatial distance between the landmarks and the goal. Landmarks near the goal more effectively overshadowed landmarks far from the goal. A second experiment, in which landmarks and orientation cues were misaligned in order to prevent the use of a straightforward solution to the task, replicated the results. The results are discussed in terms of a modification of Pearce's configural model. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Black-capped chickadees (Poecile atricapillus) and other species that feed at bird feeders balance the benefit of easy foraging with the added risk of predation. Individual birds respond differently to risky situations, and these differences have been attributed to the birds' personalities, which researchers commonly assess with an "open-field" behavioral assay. However, these behavioral assays in birds have not been compared to behavior in the wild in the context of foraging in the presence of a predator (i.e., risk-taking behavior). We color-banded chickadees in a wild population and conducted behavioral assays in the field. We later used foraging trials to investigate these color-banded individuals' responses to a predator (Cooper's hawk, Accipiter cooperii) model or a series of Cooper's hawk calls. We found that foraging black-capped chickadees responded more strongly to the presence of a predator model than to predator calls. Individual birds differed in their responses, and the behavioral assays (activity and exploration) predicted individual behavior in the wild during the foraging experiments. Activity and exploration assay scores were only weakly related, suggesting these two assays represent different traits. Both highly active birds and fast explorers exhibited some reluctance to visit the feeder (either reduced number of visits or greater latency to visit) when the predator model was present, a relationship that was somewhat unexpected. Our results suggest that standard behavioral assays predict behavior in the wild, but care should be taken when generalizing among species and studies. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Many animals, including humans, must make decisions when outcomes involve risk and/or ambiguity. To explore the evolutionary roots of decision making when outcomes are unknown, we modified the Balloon Analogue Risk Task (BART) for use with tufted capuchin monkeys (Sapajus [Cebus] apella), creating the Primate Analogue Risk Task (PART). Using both the BART and the PART, we first compared human performance across the two tasks using analogous parameters. Humans' performance on the two tasks was positively correlated. Next, we tested capuchin monkeys' performance on the PART to assess their decision-making strategies in the context of ambiguity. Secondarily, although it was not the main goal of the study, this allowed us to look at species differences between capuchins' and humans' performance. Finally, we investigated the influence of prior experience on human and capuchin decision-making behavior. Neither capuchins nor humans behaved differently following an unsuccessful trial compared to a successful trial. We found individual differences in capuchin monkeys' choice behavior, though as a whole they demonstrated a pattern of reward maximization over time. Finally, as a species, capuchins had lower PART risk scores than humans. This paradigm presents a useful way to assess behavior in a context with uncertain outcomes using a comparative approach. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Comments on an article by Jay W. Schwartz , Kayleigh H. Pierson, and Alexander K. Reece (see record 2024-19488-001). In this issue, Schwartz et al. (2024) tackle the pitch rule in humans by testing to what extent we use pitch alone to judge emotional arousal across closely and distantly related animal species. The findings of Schwartz et al. open a number of intriguing possibilities for future research: Notably important additional steps would include to further investigate the accuracy of the pitch rule across closely and distantly related species. Upon this, in order to study the evolutionary ancestry of the pitch rule, it will be necessary to study its applicability across nonhumans. Particularly interesting would be the inclusion of subject species that have been found to eavesdrop on heterospecific alarm calls. Previous research (see Hoeschele, 2017 for a review) as well as present findings on human ratings of macaque versus cricket calls also suggest that we should additionally focus on sound features that compliment emotional arousal rating beyond pitch such as spectral information. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

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).