|
|
Stöwe, M. & K., K. (2007). Behavioural phenotypes may determine whether social context facilitates or delays novel object exploration in ravens. International Journal of Ornithology, 148(Suppl 2), 179–184.
Abstract: Individuals consistently differ in behavioural phenotypes. Here we examine the interaction between behavioural phenotype and response to social context during novel object exploration in a neophobic corvid species, the raven (Corvus corax). The presence of conspecifics tends to encourage object exploration and learning but may also delay or even inhibit exploratory behaviour. Factors such as individual differences in response to social context may determine whether the presence of a conspecific facilitates or inhibits approach to novel objects. We confronted eleven six-month-old hand-raised ravens with novel objects, both individually and in dyadic combinations. We defined individuals as “fast” and “slow” explorers on the basis of their approach latency to novel objects when tested individually. The presence of a conspecific delayed the approach of fast birds to novel objects. Slow birds, in contrast, approached the novel objects with lower latencies and spent more time close to them when in dyads with fast siblings than when alone. The individuals" approach behaviour seemed to determine whether social context facilitated or delayed exploratory behaviour. This may contribute to explaining ambiguous results concerning the effects of social context in previous studies.
|
|
|
|
Graf, P., Schneider, T., KönigvonBorstel, U., & Gauly M. (2013). Kosten-Nutzen-Analyse einer objektivierten Temperamentbeurteilung bei Pferden [Economic evaluation of an objective temperament assessment in horses]. Züchtungskunde, 85(2), 129–142.
Abstract: Das Ziel der vorliegenden Studie war die Ermittlung der Kosten eines Verhaltenstests zur
objektiven Temperamentbeurteilung. Sie wurde an 1028 Pferden auf 55 Zuchtveranstaltungen
und Privatbetrieben ermittelt.
Weiterhin wurde eine Befragung zur allgemeinen Akzeptanz einer solchen Beurteilung
bei Reitpferden durchgeführt. Zusätzlich wurde mit Hilfe einer Online-Umfrage die
Meinung zu den Kosten und dem Aufwand einer solchen Beurteilung ermittelt. Die
Kosten der Einführung einer objektiven Temperamentbeurteilung entsprechen nach Einbeziehung
aller Faktoren ca. 18 Euro je Pferd. Den Kosten steht die Zahlungsbereitschaft
für eine verbesserte, da objektivierte Temperamentbeurteilung gegenüber. Insgesamt
56,7% der Befragten wären bereit, mehr als 11 Euro für eine objektive Interieurbeurteilung
auf Leistungsprüfungen im Feld zu investieren. Im Rahmen von Stationsprüfungen
wären sie sogar bereit mehr als 30 Euro aufzuwenden. Die Wertsteigerung eines im
Rahmen des Verfahrens positiv bewerteten Pferdes um 5%, die von den Teilnehmern der
Umfrage durchschnittlich angenommen wird, würde zusätzlich den Gewinn beim Pferdeverkauf
steigern. Die Ergebnisse zeigen, dass die Kosten einer objektiven Temperamentbeurteilung
durch eine erhöhte Zahlungsbereitschaft der Käufer scheinbar kompensiert
werden können, so dass die Einführung eines Temperamenttests zur objektiven Interieurbeurteilung
in Form der vorgestellten Untersuchungen grundsätzlich finanzierbar ist.
[The aim of the present study was to assess costs as well as riders’ acceptance of an
objective temperament evaluation in riding horses. Costs were determined based on a
novel object test conducted in 1028 horses tested on 65 occasions during performance
tests or in private stables. In addition, an online survey was used to identify riders’
opinion about the costs and benefits of such an assessment. Based on the conditions
assumed in the present study the costs for temperament testing have amount 18 Euro per
horse. More than 50% of the respondents were willing to pay more than 11 Euro for an
objective temperament assessment in their horses during performance tests in field.
Within performance tests on station they would spend more than 30 Euro for an objective temperament assessment. Participants further assumed a rise in value of favourably
assessed horses by 5%, leading to increased profits when selling the horse. In conclusion,
riders appear to be willing to cover the additional costs accrued from the temperament
test. Therefore, the introduction of an objective temperament assessment is likely to pay
off.]
|
|
|
|
Maros, K., Kovács, R., & Nagy, K. (2015). Questionnaire survey personality assessment of horses of different use. In K. Krueger (Ed.), Proceedings of the 3. International Equine Science Meeting. Wald: Xenophon Publishing.
Abstract: We collected data from 248 horses of different breeds, age, sex and use, forming four groups: 74 trotters, 70 gallop horses, 60 horseback archery horses and 44 police horses. All horses were trained and ridden/driven in a regular base. Caretakers or owners who were familiar with the target animals were asked to assess their horses’ temperament. The temperament scores were obtained with the 7-point scale questionnaire according to the Horse Personality Questionnaire which has 25 items and has previously been shown to be reliable for the assessment of personality in horses. It measures six personality components in horses: Dominance, Anxiousness, Excitability, Protection, Sociability and Inquisitiveness.
Component scores were calculated according to Lloyd, A.S., Martin, J.E., Bornett-Gauci, H.L.I., Wilkinson, R.G. (2008) Horse personality: Variation between breeds. Applied Animal Behaviour Science 112. 369–383. The component scores were compared across the four examined groups using the Kruskal–Wallis test. Post hoc multiple comparisons tests were then carried out to explore specific breed differences on each component. The value of alpha was set at 0.05 for all statistical tests.
Groups differed significantly regarding Anxiousness and Excitability, but no significant differences were found regarding Dominance, Protection, Sociability or Inquisitiveness among groups. This finding is in line with the findings of Lloyd et al. (2008) who showed that Anxiousness and Excitability components have the highest level of variation between breeds.In our study, gallop horses had the highest rank regarding Excitability and they differed significantly from police horses which had the lowest rank for this personality component. Interestingly gallop horses had the lowest rank regarding Anxiousness, and trotters got the highest rank in in this component.
According to our results gallop horses are the most extreme in their personality. It is conceivable that being excitable is a more favourable trait for a race horse than for a working police horse. However, it is interesting that trotters are more anxious than gallop horses since they also have a high thoroughbred ancestry. The effect of work and training on these horses needs further surveys.
|
|
|
|
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.
|
|
|
|
Stamps, J. A. (2007). Growth-mortality tradeoffs and 'personality traits' in animals. Ecol Lett, 10(5), 355–363.
Abstract: Consistent individual differences in boldness, reactivity, aggressiveness, and other 'personality traits' in animals are stable within individuals but vary across individuals, for reasons which are currently obscure. Here, I suggest that consistent individual differences in growth rates encourage consistent individual differences in behavior patterns that contribute to growth-mortality tradeoffs. This hypothesis predicts that behavior patterns that increase both growth and mortality rates (e.g. foraging under predation risk, aggressive defense of feeding territories) will be positively correlated with one another across individuals, that selection for high growth rates will increase mean levels of potentially risky behavior across populations, and that within populations, faster-growing individuals will take more risks in foraging contexts than slower-growing individuals. Tentative empirical support for these predictions suggests that a growth-mortality perspective may help explain some of the consistent individual differences in behavioral traits that have been reported in fish, amphibians, reptiles, and other animals with indeterminate growth.
|
|
|
|
Nettle, D. (2006). The evolution of personality variation in humans and other animals. Am Psychol, 61(6), 622–631.
Abstract: A comprehensive evolutionary framework for understanding the maintenance of heritable behavioral variation in humans is yet to be developed. Some evolutionary psychologists have argued that heritable variation will not be found in important, fitness-relevant characteristics because of the winnowing effect of natural selection. This article propounds the opposite view. Heritable variation is ubiquitous in all species, and there are a number of frameworks for understanding its persistence. The author argues that each of the Big Five dimensions of human personality can be seen as the result of a trade-off between different fitness costs and benefits. As there is no unconditionally optimal value of these trade-offs, it is to be expected that genetic diversity will be retained in the population.
|
|
|
|
Kralj-Fiser, S., Scheiber, I. B. R., Blejec, A., Moestl, E., & Kotrschal, K. (2007). Individualities in a flock of free-roaming greylag geese: behavioral and physiological consistency over time and across situations. Horm Behav, 51(2), 239–248.
Abstract: The concept of personality implies individual differences in behavior and physiology that show some degree of repeatability/consistency over time and across contexts. Most studies of animal personality, particularly studies of individuals' variation in physiological mechanisms, have been conducted on selected individuals in controlled conditions. We attempted to detect consistent behaviors as well as physiological patterns in greylag ganders (Anser anser) from a free-roaming flock living in semi-natural conditions. We tested 10 individuals repeatedly, in a handling trial, resembling tests for characterization of “temperaments” in captive animals. We recorded the behavior of the same 10 individuals during four situations in the socially intact flock: (1) a “low density feeding condition”, (2) a “high density feeding condition”, (3) a “low density post-feeding situation” and (4) while the geese rested. We collected fecal samples for determination of excreted immuno-reactive corticosterone (BM) and testosterone metabolites (TM) after handling trials, as well as the “low density feeding” and the “high density feeding” conditions. BM levels were very highly consistent over the repeats of handling trials, and the “low density feeding condition” and tended to be consistent over the first two repeats of the “high density feeding condition”. Also, BM responses tended to be consistent across contexts. Despite seasonal variation, there tended to be inter-test consistency of TM, which pointed to some individual differences in TM as well. Aggressiveness turned out to be a highly repeatable trait, which was consistent across social situations, and tended to correlate with an individual's resistance during handling trials. Also, “proximity to the female partner” and “sociability” – the average number of neighboring geese in a close distance while resting – were consistent. We conclude that aggressiveness, “affiliative tendencies” and levels of excreted corticosterone and testosterone metabolites may be crucial factors of personality in geese.
|
|
|
|
Lafferty, K. D. (2005). Look what the cat dragged in: do parasites contribute to human cultural diversity? Behav. Process., 68(3), 279–282.
|
|
|
|
Hoff, M. P., Nadler, R. D., & Maple, T. L. (1981). Development of infant independence in a captive group of lowland gorillas. Dev Psychobiol, 14(3), 251–265.
Abstract: In March 1976, 3 lowlands gorillas (Gorilla gorilla gorilla) were born to primiparous females living with an adult male in a large compound at the field station of the Yerkes Regional Primate Research Center of Emory University. Observations of parent and infant behavior began at the birth of the infants, using several methods of data collection. This report focuses on the development of independence in these infants over the 1st 1 1/2 years of life. As expected, measures of mother-infant contact and proximity decreased with age. Several measures suggested that infant independence developed as an interactive process between mothers and infants, with primary responsibility changing over the months of study. Maternal behaviors that served to maintain mother-infant contact were found to decrease with age, with an eventual shift to infant responsibility for contact maintenance. Additionally, the adult male appeared to influence developing independence as reflected in the maternal protectiveness evoked by his behavior.
|
|
|
|
Capitanio, J. P., & Widaman, K. F. (2005). Confirmatory factor analysis of personality structure in adult male rhesus monkeys (Macaca mulatta). Am. J. Primatol., 65(3), 289–294.
Abstract: Reports from different laboratories have suggested that nonhuman primates have somewhat similar dimensions of personality. To date, however, no attempts have been made to statistically replicate a specific factor structure. In the present report, two independent observers recorded the behavior of 58 adult male rhesus monkeys, and then rated the animals with the use of a 50-item personality instrument. A confirmatory factor analysis (CFA) of the ratings resulted in the replication of a previously described four-factor personality structure [Maninger et al., American Journal of Primatology 61:73-83, 2003]. The first two dimensions-Sociability and Confidence-showed strong loadings and are similar to Affiliation and Agency dimensions in humans. The remaining dimensions-Equability and Irritability-were less clear, and it is possible that additional traits will have to be identified before a more robust structure can be established for these dimensions.
|
|
