Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Competitive Behavior”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16Linked to original sources

Sex, competitiveness, and intimacy in same-sex friendship in Hong Kong adolescents.

One of the alleged reasons that males report lower intimacy in same-sex friendships than females is that males tend to be more competitive than females, but this assumption has not been empirically tested. In the current study, 121 Hong Kong adolescents filled out Chinese versions of the Intimate Friendship Scale and the Competitiveness Index. As predicted, females reported having more intimate same-sex relationships than males, and they scored lower on competitiveness than males. However, the correlations between scores on the Competitiveness Index and the Intimate Friendship subscales were small and nonsignificant, suggesting that the sex difference in intimacy was not a function of competitiveness.

Adolescent↗

Competitive social strategies in groups of deprived and experienced rhesus monkeys.

Behavior during competition for water was observed in 2 social groups of young rhesus monkeys (3 females, 3 males in each). Monkeys in one group were socially deprived and those in the other were socially experienced (raised with mother and agemates). Social status, based on dyadic recording of displacements at the water bottle, was predictive of a number of measures related to water consumption and social orientation in both groups, but this measure was less reliable and predictive for the experienced group than for the deprived groups, but this measure was less reliable and predictive for the experienced group than for the deprived group. A major reason for the comparatively low predictive value and reliability of status among experienced monkeys was their ability to influence the behavior of higher status members through responses directed to a 3rd party and other elaborate social strategies, many of which depended on responding to status relations between 2nd and 3rd parties. The fact that such strategies were only observed in the experienced group is a clear indication that the development of higher orders of social cognition is dependent on early social experience.

Animals↗

Consumer-driven health care marketing.

In this article, a health care marketing executive takes an opposing view: That the consumer will not only continue to exercise choice but also, at annual renewal time, veto power. In part, that is because the consumers are feeling the rising cost of health care much more directly than in the past, through ever-higher premiums, deductibles and copayments. As they assumed more of the burden of medical care delivery, consumers are becoming more knowledgeable about and discriminating toward the health care system and provider plans they are offered. They understand--as does their employer--that no longer are all health care plans alike or at parity with each other. The consumer is also demanding greater access to freedom of provider choice, quality of health care coverage.

Choice Behavior↗

The effects of clonidine on food consumption and food competition in male stumptail macaques (Macaca arctoides).

The effects of clonidine on noncompetitive and competitive feeding were examined in three adult male stumptail macaques (Macaca arctoides). Noncompetitive feeding was examined when the subjects were individually-caged or group-caged. Clonidine (1.0 mg/kg) administered IM substantially increased food consumption over control values in all subjects in both housing situations. The effects of clonidine on competitive feeding behavior were evaluated in the group-caged environment. Food competition was assessed by recording the number of chows retrieved from a common food box by each subject. Food retrieval was increased in the lowest-ranking subject when clonidine was administered to all subjects. Retrieval decreased in the middle-ranking subject and was unchanged in the highest-ranking subject. Administration of clonidine to individual subjects did not increase food retrieval. It is concluded that since the hyperphagic property of clonidine was only apparent during noncompetitive food-getting, that other drug-behavioral interactions prevented an increase in food retrieval during competitive situations.

Animals↗

Searching beneath the shelf in macaque monkeys: evidence for a gravity bias or a foraging bias?

The reasons underpinning search biases in 2 species of macaque monkeys (Macaca mulatta and Macaca arctoides) were explored over the course of 3 experiments requiring monkeys to search for a hidden food reward. The results reveal that monkeys are adept at exploiting perceptual cues to locate a food reward but are unable to use physical constraints such as solidity as cues to the reward's location. Monkeys prefer to search for a food reward beneath a solid shelf, not because they have an expectation that the reward should be there, but rather because, in the absence of usable cues, this bias emerges as a default search option. It is hypothesized that this bias may have its roots in a history of competition for food resources.

Animals↗

Effect of motivational climate on sportspersonship among competitive youth male and female football players.

The purpose of this study was to investigate the influence of perceived motivational climate and gender on sportspersonship behavior of competitive youth football players. Participants were 512 boy and 202 girl Norwegian youth football players (12-14 years old) competing in an international football tournament. A 2 x 2 x 2 (gender, mastery climate high and low, performance climate high and low) MANOVA produced no multivariate or interaction effects, but main effects for gender, performance climate, and mastery climate did emerge. Post hoc analyses of the simple main effects found that boys and girls were different in sportspersonship, but only in that boys were more sportspersonlike than girls on one of the four sportspersonship dimensions. Players perceiving a high mastery climate endorsed sportspersonship more than those players perceiving a low mastery climate, and players perceiving a high performance climate were less likely to endorse sportspersonship than players perceiving a low performance climate. Canonical correlation analysis revealed that a strong mastery climate was positively associated with commitment, respect for social conventions, and respect for rules and officials. A strong performance climate was negatively associated with respect and concern for social conventions and respect for rules and officials, while a positive association emerged for respect and concern for the opponent. The results of our study suggest that both boys and girls may well perceive the coach emphasizing similar criteria of success and failure and thereby a similar culture of sportspersonship, while in general a strong mastery climate leads to a higher sportspersonship orientation.

Adolescent↗

Competitive sorption-desorption behavior of triazine herbicides with plant cuticular fractions.

Sorption interactions of plant cuticular matter with organic compounds are not yet fully understood. The objective of this study was to examine the competitive sorption-desorption interactions of the triazine herbicides (atrazine and ametryn) with cuticular fractions isolated from tomato fruits and leaves of Agave americana. The 13C NMR data suggest a rubber-like nature for the cutin. This biopolymer exhibited reversible and noncompetitive sorption. Enhanced desorption of atrazine was recorded in the bi-solute system with bulk and dewaxed A. americana cuticles. 13C NMR analyses of these samples suggested that the sorbed competitor ametryn facilitated a physical phase transition of rigid paraffinic sorption domain to mobile and flexible domain during sorption process. We suggest that the different sorption-desorption behavior obtained for the two cuticles is related to the higher content of waxes (14% vs 2.6%) and lower content of cutin (46% vs 75%) in the A. americana versus tomato fruit cuticle.

Absorption↗

Female intrasexual competition decreases female facial attractiveness.

Evolutionary theory predicts that female intrasexual competition will occur when males of high genetic quality are considered to be a resource. It is probable that women compete in terms of attractiveness since this is one of the primary criteria used by men when selecting mates. Furthermore, because hormones influence the mate-selection process, they may also mediate competition. One competitive strategy that women use is derogation--any act intended to decrease a rival's perceived value. To investigate intrasexual competition through derogation, the influence of oestrogen on women's ratings of female facial attractiveness was examined. During periods of high oestrogen, competition, and hence derogation, increased, as evidenced by lower ratings of female facial attractiveness. By contrast, oestrogen levels did not significantly affect ratings of male faces. These findings support the theory of female intrasexual competition with respect to attractiveness.

Analysis of Variance↗

Intragroup lethal aggression in wild spider monkeys.

We report the first evidence of intragroup coalitionary aggression leading to the death of a wild young adult male spider monkey. During a long-term study of a well-habituated community at the Otoch Ma'ax Yetel Kooh reserve in Yucatan, Mexico, a young adult male sustained severe injuries repeatedly between January and March 2002. On 1 April 2002 the same male was the victim of an intragroup attack by at least one adult male that resulted in his death. We highlight several causes of intragroup aggression that may account for the killing.

Aggression↗

The effects of azaperone, a sedative neuroleptic of the butyrophenone series, on dominant-subordinate behaviour in wistar rats competing for food.

The effects of azaperone, a sedative neuroleptic of the butyrophenone series with outstanding anti-aggressive and anti-shock activity on dominant-subordinate relationship in pairs of rats, competing for food, are described. Treating the dominant rat of a pair with azaperone, a dose related weakening (at 0.16 and 0.31 mg/kg) and reversal (at 0.63 mg/kg and above) of the initial strong dominant-subordinate relationship is demonstratedmat 5 mg/kg the dominant-subordinate reversal is complete until the end of the test session. Dominant-subordinate relationships are modified by azaperone at doses far below those inducing gross behavioural changes. The present results point at a normalizing effect of azaperone on social interaction through inhibition of aggressive responsiveness.

Aggression↗

Audience effects on food caching in grey squirrels (Sciurus carolinensis): evidence for pilferage avoidance strategies.

If food pilferage has been a reliable selection pressure on food caching animals, those animals should have evolved the ability to protect their caches from pilferers. Evidence that animals protect their caches would support the argument that pilferage has been an important adaptive challenge. We observed naturally caching Eastern grey squirrels (Sciurus carolinensis) in order to determine whether they used any evasive tactics in order to deter conspecific and heterospecific pilferage. We found that grey squirrels used evasive tactics when they had a conspecific audience, but not when they had a heterospecific (corvid) audience. When other squirrels were present, grey squirrels spaced their caches farther apart and preferentially cached when oriented with their backs to other squirrels, but no such effect was found when birds were present. Our data provide the first evidence that caching mammals are sensitive to the risk of pilferage posed by an audience of conspecifics, and that they utilise evasive tactics that should help to minimise cache loss. We discuss our results in relation to recent theory of reciprocal pilferage and compare them to behaviours shown by caching birds.

Animals↗

Hormonal correlates of siblicide in Nazca boobies: support for the Challenge Hypothesis.

The androgen hormone testosterone (T) mediates vertebrate aggression in many contexts and according to the Challenge Hypothesis is up-regulated during social challenges. While originally applied to challenges experienced by breeding adults, we show for the first time that T is similarly up-regulated during deadly sibling aggression in young birds. When two nestling Nazca boobies hatch, one--usually the older chick--virtually always kills the other chick by pushing it from the nest. We compared concentrations of T, dehydroepiandrosterone (DHEA; a precursor of T), and corticosterone (Cort; a stress hormone) of chicks at various stages. T was elevated during fights in both chicks in two-chick broods, but not before and after fights, and not in chicks lacking a nest mate. DHEA was elevated 1 day after hatching and declined with age but appeared not to vary in concert with aggression. Cort did not vary across fighting and nonfighting periods. In conjunction with an earlier study [Tarlow, E.M., Wikelski, M., Anderson, D.J., 2001. Hormonal correlates of siblicide in Galapagos Nazca boobies. Horm. Behav. 40:14-20], these results indicate that T is temporarily up-regulated around the time of fights, as predicted by the Challenge Hypothesis. Our data suggest a general role for T during challenges at any time in life, not just during breeding.

Agonistic Behavior↗

Human aggression in evolutionary psychological perspective.

This article proposes an evolutionary psychological account of human aggression. The psychological mechanisms underlying aggression are hypothesized to be context-sensitive solutions to particular adaptive problems of social living. Seven adaptive problems are proposed for which aggression might have evolved as a solution--co-opting the resources of others, defending against attack, inflicting costs on same-sex rivals, negotiating status and power hierarchies, deterring rivals from future aggression, deterring mates from sexual infidelity, and reducing resources expended on genetically unrelated children. We outline several of the contexts in which humans confront these adaptive problems and the evolutionary logic of why men are cross-culturally more violently aggressive than women in particular contexts. The article concludes with a limited review of the empirical evidence surrounding each of the seven hypothesized functions of aggression and discusses the status and limitations of the current evolutionary psychological account.

Aggression↗

Neonatal 6-hydroxydopamine alters the behavior of enriched-impoverished rats in a novel test environment.

The hypothesis that neonatal norepinephrine (NE) depletion lessens the behavioral consequences of differential housing was tested. Male Wistar rats were injected with 6-hydroxydopamine (6-OHDA) or vehicle twice within 24 hr of birth, weaned at 25 days, and reared under either impoverished (IC) or enriched conditions (EC) for 30 days. In 3 experiments, rats were tested in the Morris water maze, the colony-intruder test, and 2 tests of dominance. 6-OHDA treatment reduced cortical and hypothalamic NE concentrations and increased brainstem NE concentrations. EC housing increased cortical dopamine (DA). Behavioral differences caused by postweaning enrichment-isolation were reduced by neonatal NE depletion, primarily in early test trials. The authors conclude that forebrain NE afferents from the locus coeruleus are important for housing-related behavioral changes and responsivity to novel testing environments.

Agonistic Behavior↗