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Adolphs, R. (2003). Cognitive neuroscience of human social behaviour. Nat Rev Neurosci, 4(3), 165–178.
Abstract: We are an intensely social species--it has been argued that our social nature defines what makes us human, what makes us conscious or what gave us our large brains. As a new field, the social brain sciences are probing the neural underpinnings of social behaviour and have produced a banquet of data that are both tantalizing and deeply puzzling. We are finding new links between emotion and reason, between action and perception, and between representations of other people and ourselves. No less important are the links that are also being established across disciplines to understand social behaviour, as neuroscientists, social psychologists, anthropologists, ethologists and philosophers forge new collaborations.
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Herbert Gintis, Samuel Bowles, Robert Boyd, & Ernst Fehr. (2003). Explaining altruistic behavior in humans. Evolution and Human Behaviour, 24(3), 153–172.
Abstract: Recent experimental research has revealed forms of human behavior involving interaction among unrelated individuals that have proven difficult to explain in terms of kin or reciprocal altruism. One such trait, strong reciprocity is a predisposition to cooperate with others and to punish those who violate the norms of cooperation, at personal cost, even when it is implausible to expect that these costs will be repaid. We present evidence supporting strong reciprocity as a schema for predicting and understanding altruism in humans. We show that under conditions plausibly characteristic of the early stages of human evolution, a small number of strong reciprocators could invade a population of self-regarding types, and strong reciprocity is an evolutionary stable strategy. Although most of the evidence we report is based on behavioral experiments, the same behaviors are regularly described in everyday life, for example, in wage setting by firms, tax compliance, and cooperation in the protection of local environmental public goods.
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Povinelli, D. J., & Vonk, J. (2003). Chimpanzee minds: suspiciously human? Trends. Cognit. Sci., 7(4), 157–160.
Abstract: Chimpanzees undoubtedly form concepts related to the statistical regularities in behavior. But do they also construe such abstractions in terms of mental states – that is, do they possess a [`]theory of mind'? Although both anecdotal and experimental data have been marshaled to support this idea, we show that no explanatory power or economy of expression is gained by such an assumption. We suggest that additional experiments will be unhelpful as long as they continue to rely upon determining whether subjects interpret behavioral invariances in terms of mental states. We propose a paradigm shift to overcome this limitation.
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Miklósi, Á., Kubinyi, E., Topál, J., Gácsi, M., Virányi, Z., & Csányi, V. (2003). A Simple Reason for a Big Difference: Wolves Do Not Look Back at Humans, but Dogs Do. Current Biology, 13(9), 763–766.
Abstract: The present investigations were undertaken to compare interspecific communicative abilities of dogs and wolves, which were socialized to humans at comparable levels. The first study demonstrated that socialized wolves were able to locate the place of hidden food indicated by the touching and, to some extent, pointing cues provided by the familiar human experimenter, but their performance remained inferior to that of dogs. In the second study, we have found that, after undergoing training to solve a simple manipulation task, dogs that are faced with an insoluble version of the same problem look/gaze at the human, while socialized wolves do not. Based on these observations, we suggest that the key difference between dog and wolf behavior is the dogs' ability to look at the human's face. Since looking behavior has an important function in initializing and maintaining communicative interaction in human communication systems, we suppose that by positive feedback processes (both evolutionary and ontogenetically) the readiness of dogs to look at the human face has lead to complex forms of dog-human communication that cannot be achieved in wolves even after extended socialization.
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Shapiro, A. D., Janik, V. M., & Slater, P. J. B. (2003). A gray seal's (Halichoerus grypus) responses to experimenter-given pointing and directional cues. J Comp Psychol, 117(4), 355–362.
Abstract: A gray seal (Halichoerus grypus) was trained to touch a target on its left or right by responding to pointing signals. The authors then tested whether the seal would be able to generalize spontaneously to altered signals. It responded correctly to center pointing and head turning, center upper body turning, and off-center pointing but not to head turning and eye movements alone. The seal also responded correctly to brief ipsilateral and contralateral points from center and lateral positions. Pointing gestures did not cause the seal to select an object placed centrally behind it. Like many animals in similar studies, this gray seal probably did not understand the referential character of these gestures but rather used signal generalization and experience from initial operant conditioning to solve these tasks.
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Breuer, K., Sutcliffe, M. E. M., Mercer, J. T., Rance, K. A., Beattie, V. E., Sneddon, I. A., et al. (2003). The effect of breed on the development of adverse social behaviours in pigs. Appl. Anim. Behav. Sci., 84(1), 59–74.
Abstract: Tail-biting and other harmful social behaviours are a common problem on pig farms. The aims of the current experiment were (1) to investigate the genetic component of harmful social behaviours such as tail-biting by assessing breed differences, and (2) to further investigate the reliability and predictability of a test, [`]the tail-chew test', previously identified as potentially being capable of predicting a pig's predisposition for tail- and ear-biting. The behaviour of three pig breeds (Large White (LW), Landrace (LR), Duroc (DR)), with 100 pigs per breed, was observed in a [`]tail-chew test', and by observing the performance of harmful social behaviour directed to pen mates in flat deck pens after weaning. The tail-chew test, carried out on two consecutive days pre-weaning, involved observing the behaviour of individual pigs towards two suspended ropes. Pigs were weaned at 28 days and the occurrence of harmful social behaviour was recorded 4 weeks later over 2 consecutive days (1 h per day) using a group [`]period occurrence' scanning method. Breed had a significant effect on rope-directed behaviour in the tail-chew test and on harmful social behaviour. DR pigs interacted with the ropes in the tail-chew test more often (median 23.0 vs 19.0 and 17.5 times in 20 min, P<0.001) and for longer (31.0 vs 20.0 and 23.2 s, P<0.001) than LR and LW pigs, respectively. Although not significantly different from LW, DR pigs tended to direct more total harmful social behaviour towards pen mates than the other breeds. In particular, DR were observed in more total pig-directed biting of pen mates (median 9.0 vs 6.0 and 7.0, P<0.01) than LR and LW, and tended to nose pen mates more often than the other breeds (13.0 vs 11.0 and 10.0, P=0.06). LR pigs bit the ears of pen mates less often than LW and DR (4.0 vs 5.0 and 6.0, P<0.001). Belly-nosing activity was low, with a median of 0 for all breeds, but LR belly-nosed pen mates more often than Durocs (interquartile ranges 0-2.0 vs 0-1.0 and 0-1.0, P<0.01). The behaviour observed in the tail-chew test on day 1 correlated significantly with that observed on day 2 of the test (e.g. frequency of rope-directed behaviour rs=0.380,P<0.01). There were significant but weak correlations between rope-directed behaviour and the performance of some harmful social behaviours. The significant breed differences indicate some genetic contribution to expression of harmful social behaviours. However, the tail-chew test was found to be of limited ability to predict tail- and ear-biting under commercial conditions.
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Breuer, K., Hemsworth, P. H., & Coleman, G. J. (2003). The effect of positive or negative handling on the behavioural and physiological responses of nonlactating heifers. Appl. Anim. Behav. Sci., 84(1), 3–22.
Abstract: This experiment investigated the effects of positive and negative tactile handling on the stress physiology and behaviour of dairy heifers. Forty-eight 5-14-month-old nonlactating Holstein-Friesian heifers were allocated to one of two handling treatments, either positive or negative tactile handling, over four time replicates. Handling was imposed twice daily, 2-5 min per session and involved moving animals individually along a 64 m outdoor route. The negatively handled heifers took longer to approach within 1 and 2 m of a stimulus person in a standard test, than their positively handled counterparts (P<0.001) and had a greater flight distance to an approaching stimulus (P<0.001). The time taken by the heifers to approach within 1 and 2 m of a familiar person was similar to that taken to approach within 1 and 2 m of an unfamiliar person in the standard test (P<0.05). There was a tendency for heifers to have a greater flight distance from the approaching unfamiliar person than from the approaching familiar person (P=0.06). The negatively handled heifers had greater (P<0.05) increases in total cortisol concentrations 5, 10 and 15 min after exposure to a human and had higher (P<0.05) free cortisol concentrations in the afternoon than the positively handled heifers. It is concluded that the nature of the human contact affects the subsequent behavioural response of heifers to humans. This behavioural response may extend to other humans through the process of stimulus generalisation, although there was some evidence of moderate discrimination. Negative handling results in an acute stress response in the presence of humans and also leads to a chronic stress response. Further research into the effect of these stress responses on milk production and welfare in fearful cows in a commercial situation is suggested.
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Scheibe, K. M., & Streich, W. J. (2003). Annual Rhythm of Body Weight in Przewalski Horses (Equus ferus przewalskii). Biological Rhythm Research, 34(4), 383–395.
Abstract: The live-weight of female Przewalski horses in a semi-natural reserve has been recorded continuously over 6 years by means of an automatic weighing machine and automatic identification. Data were tested for cyclic as well as for linear trend effects and a mathematical model was developed. A clear annual rhythm of live-weight with the maximum in October was demonstrated. During the first 2 years of recording, the level of the annual rhythm was constant but, thereafter, different individual trends were found. Those individuals showing a steeply rising trend suffered from laminitis after three annual cycles. The periods of rising body weight corresponded to unusual mild winters. Animals newly introduced into the reserve from zoos showed a rise in their body weight in an adaptation phase. Furthermore, there was evidence for a phase adjustment of the annual rhythm. The results are discussed against a background of the theory of annual rhythms, and can be used as a basis for seasonal variations of feeding in zoos and for a re-evaluation of recommendations for population density in similar reserves. For reintroductions as well as for a transfer from zoos to semi-natural reserves, a longer adaptation phase is recommended.
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Rüegg J. C. (2003). Psychosomatik, Psychotherapie und Gehirn. Stuttgart: Schattauer Verlag.
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Wallner, B., Brem, G., Muller, M., & Achmann, R. (2003). Fixed nucleotide differences on the Y chromosome indicate clear divergence between Equus przewalskii and Equus caballus. Anim Genet, 34(6), 453–456.
Abstract: The phylogenetic relationship between Equus przewalskii and E. caballus is often a matter of debate. Although these taxa have different chromosome numbers, they do not form monophyletic clades in a phylogenetic tree based on mtDNA sequences. Here we report sequence variation from five newly identified Y chromosome regions of the horse. Two fixed nucleotide differences on the Y chromosome clearly display Przewalski's horse and domestic horse as sister taxa. At both positions the Przewalski's horse haplotype shows the ancestral state, in common with the members of the zebra/ass lineage. We discuss the factors that may have led to the differences in mtDNA and Y-chromosomal observations.
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