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Weed M.R., Taffe M.A., Polis I., Roberts A.C., Robbins T.W., Koob G.F., et al. (1999). Performance norms for a rhesus monkey neuropsychological testing battery: acquisition and long-term performance. Cognitive Brain Research, 8, 185–201.
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Weckerly, F. W. (1999). Social bonding and aggression in female Roosevelt elk. Can J Zool, 77(9), 1379–1384.
Abstract: Abstract: The relationship between degree of social bonding (extent of association among individuals) and level of aggression in ruminants is unclear. I examined social bonding and aggression in three groups of female Roosevelt elk (Cervus elaphus roosevelti) over 2 years. I hypothesized that when animals are socially bonded, bouts of aggression will be won by the individual initiating the aggression, occur quickly, and involve little physical contact, and the level of aggression does not correlate with group size. The degree of social bonding was high among individuals in all groups. Dyads of known individuals were together >80% of the time. A permutation analysis indicated that groups with the observed sizes had <0.001 chance of random association, except on one occasion when the probability was 0.72 for one group. Using focal-animal sampling, aggressive interactions were won 72% of the time by the initiator, occurred quickly (<5 s), and involved little physical contact, and the level of aggression was not correlated with group size. The level of aggression was, however, significantly lower in one of the groups. This group may have had access to more abundant food resources than the other groups. Socially bonded elk conducted aggressive interactions in a fashion that did not disrupt social stability. Résumé : La relation entre le degré de liaison sociale (importance des associations entre individus) et l`agressivité n`est pas claire chez les ruminants. J`ai étudié les liaisons sociales et l`agressivité chez trois groupes de femelles du Cerf de Roosevelt (Cervus elaphus roosevelti) pendant 2 ans. J`ai posé en hypothèse que, chez les animaux liés socialement, la victoire devrait être emportée par l`individu qui entreprend l`agression, l`agression devrait être de courte durée, se faire avec peu de contacts physiques et la fréquence des agressions ne devrait pas être liée à la taille du groupe. Des paires d`individus passaient plus de 80% de leur temps ensemble. Une analyse des permutations a démontré que, chez les groupes des tailles observées, la probabilité d`une association aléatoire était de moins de 0,001, sauf en un cas où cette probabilité a été évaluée à 0,72 chez un groupe. Par échantillonnage directionnel, j`ai observé que les interactions agressives étaient gagnées par l`individu attaquant 72% du temps, étaient de courte durée (<5 s), se faisaient avec peu de contacts physiques et leur fréquence n`était pas reliée à la taille du groupe. Il y avait cependant moins d`agressivité chez l`un des groupes. Il se peut que ce groupe ait eu accès à plus de ressources alimentaires que les autres. Chez les cerfs liés par des liens sociaux, l`agressivité ne se manifeste pas de façon à déséquilibrer la stabilité sociale.
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Webster, S., & Fiorito, G. (2001). Socially guided behaviour in non-insect invertebrates. Anim. Cogn., 4(2), 69–79.
Abstract: A review of the past 50 years of literature on socially guided behaviour addresses two questions: (1) whether socially guided behaviour, which has traditionally been considered characteristic of vertebrates, is also found among non-insect invertebrates, and (2) to see whether our classification of socially guided behaviours in invertebrates matches, and thereby supports, A. Whiten and R. Ham's classification of vertebrate behaviours into two broad categories, social learning and social influence. We systematically reviewed the literature on socially guided behaviour in non-insect invertebrates to determine if social behaviours exist. Once this was established, we characterised our findings using 13 behavioural phenomena that are considered to be descriptive of socially guided behaviour. Using a multivariate technique, we then analysed the data to determine if our characterisation scheme produced a similar distribution to that presented by A. Whiten and R. Ham. Our results indicate that socially guided behaviours are present in invertebrates, and invertebrates can be placed into the previously established framework on vertebrate social behaviour. Further, our analysis reveals a prominent separation between representations of the social influence and social learning categories, thereby supporting the previously published framework on socially guided behaviour.
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Webster, M. M., & Laland, K. N. (2008). Social learning strategies and predation risk: minnows copy only when using private information would be costly. Proc. R. Soc. Lond. B, 275(1653), 2869–2876.
Abstract: Animals can acquire information from the environment privately, by sampling it directly, or socially, through learning from others. Generally, private information is more accurate, but expensive to acquire, while social information is cheaper but less reliable. Accordingly, the 'costly information hypothesis' predicts that individuals will use private information when the costs associated with doing so are low, but that they should increasingly use social information as the costs of using private information rise. While consistent with considerable data, this theory has yet to be directly tested in a satisfactory manner. We tested this hypothesis by giving minnows (Phoxinus phoxinus) a choice between socially demonstrated and non-demonstrated prey patches under conditions of low, indirect and high simulated predation risk. Subjects had no experience (experiment 1) or prior private information that conflicted with the social information provided by the demonstrators (experiment 2). In both experiments, subjects spent more time in the demonstrated patch than in the non-demonstrated patch, and in experiment 1 made fewer switches between patches, when risk was high compared with when it was low. These findings are consistent with the predictions of the costly information hypothesis, and imply that minnows adopt a 'copy-when-asocial-learning-is-costly' learning strategy.
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Webster G,. (1956). Unsung empire builder – The male. Nat Hist, , 130–135.
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Weber-Mzell, D., Kotanko, P., Hauer, A. C., Goriup, U., Haas, J., Lanner, N., et al. (2004). Gender, age and seasonal effects on IgA deficiency: a study of 7293 Caucasians. European Journal of Clinical Investigation, 34(3), 224–228.
Abstract: Background The frequency of serum IgA deficiency (SIgAD) differs between populations. We examined the prevalence of SIgAD in healthy Caucasians. Materials and methods Serum immunoglobulin A (SIgA) was measured in 7293 volunteers (2264 women, 5029 men) aged 30 ± 14·2 years (mean ± SD; range: 12–66). Serum immunoglobulin A and subnormal SIgA levels were defined by a SIgA level < 0·07 g L-1, and between 0·07 and 0·7 g L-1, respectively. Means were compared by analysis of variance (anova) and analysis of covariance (ancova); frequencies by the χ2 test. Results Fifteen subjects (0·21%; one woman, 14 men) had SIgAD. Subnormal SIgA levels were found in 155 persons (2·13%): 21 females (0·93% of the females) and 134 males (2·66% of the males; difference: 1·74%; 95% CI: 1·12–2·33%; P < 0·001). Males were more likely to have subnormal SIgA levels or SIgAD (odds ratio 3·09, 95% CI: 1·97–4·85). The prevalence of SIgAD and subnormal SIgA was lowest in winter (χ2 = 14·8; P = 0·002; 3 d.f.; and χ2 = 43·2; P < 0·001; 3 d.f., respectively). Serum immunoglobulin A concentrations were significantly higher during winter. Serum immunoglobulin A levels increased with age on average by 0·2 ± 0·06 g L-1 per decade of life (P < 0·001). Taking into account the influence of age, SIgA concentration was lower in females as compared with males. Conclusion The prevalence of SIgAD and subnormal SIgA levels is increased in males. There exists a significant influence of gender, age and seasons on SIgA levels.
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Weaver, A., & de Waal, F. B. M. (2003). The mother-offspring relationship as a template in social development: reconciliation in captive brown capuchins (Cebus apella). J Comp Psychol, 117(1), 101–110.
Abstract: Mother-offspring (MO) relationship quality was investigated to determine its influence on the development of reconciliation--affiliation between opponents shortly after a fight--because it influenceswhat distressed youngsters learn about calming down. Data were longitudinal and cross-sectional observational samples of 38 MO pairs of monkeys across 24 months. An MO relationship quality index (RQI) classified each pair as secure or insecure. Reconciliation emerged in infancy.Secure youngsters had an appeasing conciliatory style, and insecure youngsters had an agitated conciliatory style. Conclusions are that reconciliation develops from the attachment behavior system and MO RQI is related to the particular conciliatory style youngsters develop by affecting how aroused they are by conflict and the subsequent socializing they seek to calm down.
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Weaver, A., & de Waal, F. B. M. (2002). An index of relationship quality based on attachment theory. J Comp Psychol, 116(1), 93–106.
Abstract: Two measures are reported of the nature or quality of a mother-offspring (MO) relationship during development using brown capuchin monkeys (Cebus apella) as models. One is a qualitative classification of MO relationships as secure, resistant, or avoidant attachments. The other is an empirical ratio of relative affiliation to agonism called the MO relationship quality, or MORQ, Index. The two methods tapped similar relationship features so relationships high or low of a median split of MORQ values were heuristically labeled secure (n = 22) or insecure (n = 16), respectively. A comparison revealed extensive behavioral differences between secure and insecure MO relationships and suggested MORQ provided an objective, continuous measure of attachment security.
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Weatherly, J. N., Arthur, E. I. L., & Tischart, L. M. (2003). Altering “motivational” variables alters induction produced by upcoming food-pellet reinforcement. Anim. Cogn., 6(1), 17–26.
Abstract: Previous research has demonstrated that rats will increase their rates of lever pressing for sucrose rewards in the first half of an experimental session when food pellets, rather than the same sucrose, continually serve as the reward in the second half of the session. This effect has been coined induction, and the present study investigated whether it could be altered by altering “motivational” variables. Experiment 1 manipulated subjects' motivation by altering, across conditions, their level of food deprivation. Predictably, the size of induction varied directly with level of deprivation. Experiments 2 and 3 manipulated subjects' motivation by feeding them food pellets and sucrose, respectively, prior to their responding in the experimental session. These pre-session feedings decreased the size of the observed induction in both experiments. The results from the present study indicate that the size of induction is correlated with subjects' motivation to respond for the available reinforcers. They are also consistent with the idea that operant processes underlie the effect. The notion that induction might encompass the concept of “anticipation” is also discussed.
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WAYNE L. LINKLATER & ELISSA Z. CAMERON. (2000). Distinguishing cooperation from cohabitation: the feral horse case. Anim. Behav., 59, F17–F21.
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