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Fragaszy, D., & Visalberghi, E. (2004). Socially biased learning in monkeys. Learn Behav, 32(1), 24–35.
Abstract: We review socially biased learning about food and problem solving in monkeys, relying especially on studies with tufted capuchin monkeys (Cebus apella) and callitrichid monkeys. Capuchin monkeys most effectively learn to solve a new problem when they can act jointly with an experienced partner in a socially tolerant setting and when the problem can be solved by direct action on an object or substrate, but they do not learn by imitation. Capuchin monkeys are motivated to eat foods, whether familiar or novel, when they are with others that are eating, regardless of what the others are eating. Thus, social bias in learning about foods is indirect and mediated by facilitation of feeding. In most respects, social biases in learning are similar in capuchins and callitrichids, except that callitrichids provide more specific behavioral cues to others about the availability and palatability of foods. Callitrichids generally are more tolerant toward group members and coordinate their activity in space and time more closely than capuchins do. These characteristics support stronger social biases in learning in callitrichids than in capuchins in some situations. On the other hand, callitrichids' more limited range of manipulative behaviors, greater neophobia, and greater sensitivity to the risk of predation restricts what these monkeys learn in comparison with capuchins. We suggest that socially biased learning is always the collective outcome of interacting physical, social, and individual factors, and that differences across populations and species in social bias in learning reflect variations in all these dimensions. Progress in understanding socially biased learning in nonhuman species will be aided by the development of appropriately detailed models of the richly interconnected processes affecting learning.
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Fox, N. A. (2004). Temperament and early experience form social behavior. Ann N Y Acad Sci, 1038, 171–178.
Abstract: Individual differences in the way persons respond to stimulation can have important consequences for their ability to learn and their choice of vocation. Temperament is the study of such individual differences, being thought of as the behavioral style of an individual. Common to all approaches in the study of temperament are the notions that it can be identified in infancy, is fairly stable across development, and influences adult personality. We have identified a specific temperament type in infancy that involves heightened distress to novel and unfamiliar stimuli. Infants who exhibit this temperament are likely, as they get older, to display behavioral inhibition-wariness and heightened vigilance of the unfamiliar-particularly in social situations. Our work has also described the underlying biology of this temperament and has linked it to neural systems supporting fear responses in animals. Children displaying behavioral inhibition are at-risk for behavioral problems related to anxiety and social withdrawal.
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Fortes, A. F., Merchant, H., & Georgopoulos, A. P. (2004). Comparative and categorical spatial judgments in the monkey: “high” and “low”. Anim. Cogn., 7(2), 101–108.
Abstract: Adult human subjects can classify the height of an object as belonging to either of the “high” or “low” categories by utilizing an abstract concept of midline that divides the vertical dimension into two halves. Children lack this abstract concept of midline, do not have a sense that these categories are directional opposites, and their categorical and comparative usages of high(er) or low(er) are restricted to the corresponding poles. We investigated the abilities of a rhesus monkey to perform categorical judgments in space. We were also interested in the presence of the congruity effect (a decrease in response time when the objects compared are closer to the category pole) in the monkey. The presence of this phenomenon in the monkey would allow us to relate the behavior of the animal to the two major competing hypotheses that have been suggested to explain the congruity effect in humans: the analog and semantic models. The monkey was trained in delayed match-to-sample tasks in which it had to categorize objects as belonging to either a high or low category. The monkey was able to generate an abstract notion of midline in a fashion similar to that of adult human subjects. The congruity effect was also present in the monkey. These findings, taken together with the notion that monkeys are not considered to think in propositional terms, may favor an analog comparison model in the monkey.
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Flack, J. C., Jeannotte, L. A., & de Waal, F. B. M. (2004). Play signaling and the perception of social rules by juvenile chimpanzees (Pan troglodytes). J Comp Psychol, 118(2), 149–159.
Abstract: Prescriptive social rules are enforced statistical regularities. The authors investigated whether juvenile chimpanzees (Pan troglodytes) recognize and use enforced statistical regularities to guide dyadic play behavior. They hypothesized (a) that proximity of adults, especially mothers of younger play partners, to play bouts will increase the play signaling of older partners and (b) that when juvenile-juvenile play bouts occur in proximity to adults, older partners will play at a lower intensity than when no adults are present. They found that older and younger partners increase their play signaling in the presence of the mothers of younger partners, particularly as the intensity of play bouts increases. In contrast to their hypothesis, older partners played more roughly when the mothers of younger partners were in proximity. These results suggest that juvenile chimpanzees increase play signaling to prevent termination of the play bouts by mothers of younger partners.
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Fichtel, C. (2004). Reciprocal recognition of sifaka ( Propithecus verreauxi verreauxi) and redfronted lemur ( Eulemur fulvus rufus) alarm calls. Anim. Cogn., 7(1), 45–52.
Abstract: Redfronted lemurs ( Eulemur fulvus rufus) and Verreaux's sifakas ( Propithecus verreauxi verreauxi) occur sympatrically in western Madagascar. Both species exhibit a so-called mixed alarm call system with functionally referential alarm calls for raptors and general alarm calls for carnivores and raptors. General alarm calls also occur in other contexts associated with high arousal, such as inter-group encounters. Field playback experiments were conducted to investigate whether interspecific recognition of alarm calls occurs in both species, even though the two species rarely interact. In a crossed design, redfronted lemur and sifaka alarm calls were broadcast to individuals of both species, using the alarm call of chacma baboons ( Papio cynocephalus) as a control. Both species responded with appropriate escape strategies and alarm calls after playbacks of heterospecific aerial alarm calls. Similarly, they reacted appropriately to playbacks of heterospecific general alarm calls. Playbacks of baboon alarm calls elicited no specific responses in either lemur species, indicating that an understanding of interspecific alarm calls caused the responses and not alarm calls in general. Thus, the two lemur species have an understanding of each other's aerial as well as general alarm calls, suggesting that even in species that do not form mutualistic associations and rarely interact, common predator pressure has been sufficient for the development of heterospecific call recognition.
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Fenton, B., & Ratcliffe, J. (2004). Animal behaviour: eavesdropping on bats. Nature, 429(6992), 612–613. |
Evans, T. A., & Westergaard, G. C. (2004). Discrimination of functionally appropriate and inappropriate throwing tools by captive tufted capuchins (Cebus apella). Anim. Cogn., 7(4), 255–262.
Abstract: A tool-throwing task was used to test whether capuchin monkeys understand the difference between functionally appropriate and functionally inappropriate tools. A group of monkeys was trained to obtain a sticky treat from a container outside their enclosure using a projectile attached to one end of an anchored line. Subsequently, these monkeys were given choice tests between functional and nonfunctional versions of tools used in training. A different feature of the tool was varied between alternatives in each choice test. The monkeys chose to use functional tools significantly more often than nonfunctional tools in early exposures to each choice test. A second experiment tested whether these subjects, as well as a second group of minimally trained participants, could distinguish between functional and nonfunctional tools that appeared different from those used in training. A new set of design features was varied between tools in these choice tests. All participants continued to choose functional tools significantly more often than nonfunctional tools, regardless of their tool-throwing experience or the novel appearance of the tools. These results suggest that capuchin monkeys, like chimpanzees studied in similar experiments, are sensitive to a variety of functionally relevant tool features.
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Eriksson, E., Royo, F., Lyberg, K., Carlsson, H. - E., & Hau, J. (2004). Effect of metabolic cage housing on immunoglobulin A and corticosterone excretion in faeces and urine of young male rats. Exp. Physiol., 89(4), 427–433.
Abstract: Six 8-week-old Sprague-Dawley rats were studied for 9 days divided into three periods of 3 days each: before transferral to metabolism cages, during metabolic cage housing and after return to their home cages. Faeces were collected daily when the animals were housed in their home cages and every 6 h when the animals were housed in metabolic cages during which time urine was also collected every 6 h. The rate of weight gain was slightly reduced during the 3 days in metabolic cages and the animals produced significantly larger amounts of faeces when housed in metabolic cages than when housed in their home cages. The total faecal excretion of corticosterone (nanograms excreted per hour per kilogram body weight) and immunoglobulin A (IgA) (milligrams excreted per hour per kg body weight) quantified by enzyme-linked immunosorbent assays (ELISAs) exhibited a clear diurnal rhythm in the metabolic cage. Urinary excretions of corticosterone and IgA also followed a clear diurnal cycle. The mean daily amounts of corticosterone excreted were not significantly affected by cage change and by housing in metabolic cages. However, the excretion of faecal IgA was significantly reduced during the 3 days after the period in metabolic cages. Taken together the results indicate that metabolic cage housing is mildly stressful for young adult male rats.
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Emery, N. J., Dally, J. M., & Clayton, N. S. (2004). Western scrub-jays ( Aphelocoma californica) use cognitive strategies to protect their caches from thieving conspecifics. Anim. Cogn., 7(1), 37–43.
Abstract: Food caching birds hide food and recover the caches when supplies are less abundant. There is, however, a risk to this strategy because the caches are susceptible to pilfering by others. Corvids use a number of different strategies to reduce possible cache theft. Scrub-jays with previous experience of pilfering other's caches cached worms in two visuospatially distinct caching trays either in private or in the presence of a conspecific. When these storers had cached in private, they subsequently observed both trays out of reach of a conspecific. When these storers had cached in the presence of a conspecific, they subsequently watched the observer pilfering from one of the trays while the other tray was placed in full view, but out of reach. The storers were then allowed to recover the remaining caches 3 h later. Jays cached more worms when they were observed during caching. At the time of recovery, they re-cached more than if they had cached in private, selectively re-caching outside of the trays in sites unbeknown to potential thieves. In addition, after a single pilfering trial, the jays switched their recovery strategy from predominantly checking their caches (i.e. returning to a cache site to see whether the food remained there) to predominantly eating them. Re-caching remained constant across the three trials. These results suggest that scrub-jays use flexible, cognitive caching and recovery strategies to aid in reducing potential future pilfering of caches by conspecifics.
Keywords: Animals; Birds/*physiology; Feeding Behavior/*physiology; Female; *Food; Male; *Memory
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Emery, N. J., & Clayton, N. S. (2004). The Mentality of Crows: Convergent Evolution of Intelligence in Corvids and Apes. Science, 306(5703), 1903–1907.
Abstract: Discussions of the evolution of intelligence have focused on monkeys and apes because of their close evolutionary relationship to humans. Other large-brained social animals, such as corvids, also understand their physical and social worlds. Here we review recent studies of tool manufacture, mental time travel, and social cognition in corvids, and suggest that complex cognition depends on a “tool kit” consisting of causal reasoning, flexibility, imagination, and prospection. Because corvids and apes share these cognitive tools, we argue that complex cognitive abilities evolved multiple times in distantly related species with vastly different brain structures in order to solve similar socioecological problems.
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