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1.
AimThe present study attempted to test McCullough and Willoughby’s hypothesis that self-control mediates the relationships between religiosity and psychosocial outcomes. Specifically, this study examined whether trait self-control (TSC) mediates the relationship of identified-introjected religiosity with positive and negative health-related-feelings (HRF) in healthy Muslims.MethodsTwo hundred eleven French-speaking participants (116 females, 95 males; Mage = 28.15, SDage = 6.90) answered questionnaires. One hundred ninety participants were retained for the analyses because they reported to be healthy (105 females, 85 males; Mage = 27.72, SDage = 6.80). To examine the relationships between religiosity, TSC and HRF, two competing mediation models were tested using structural equation model analysis: While a starting model used TSC as mediator of the religiosity-HRF relationship, an alternative model used religiosity as mediator of the TSC-HRF relationship.ResultsThe findings revealed that TSC mediated the relationship between identified religiosity and positive HRF, and that identified religiosity mediated the relationship between TSC and positive and negative HRF, thereby validating both models. Moreover, the comparison of both models showed that the starting model explained 13.211% of the variance (goodness of fit = 1.000), whereas the alternative model explained 6.877% of the variance (goodness of fit = 0.987).ConclusionThese results show that the starting model is the most effective model to account for the relationships between religiosity, TSC, and HRF. Therefore, this study provides initial insights into how religiosity influences psychological health through TSC. Important practical implications for the religious education are suggested.  相似文献   

2.
《Bird Study》2012,59(3):329-341
ABSTRACT

Capsule: In Egyptian Vultures Neophron percnopterus, both sexes invested similar parental effort throughout the breeding period. However, there was variation in the degree of intensity of parental care during some stages of the breeding period, suggesting that sex-role specialization exists for some activities.

Aims: To quantify parental care behaviour of Egyptian Vultures for the first time and to examine the role of sex, weather conditions, and stage of nesting cycle on breeding ecology.

Methods: We monitored 15 nests of Egyptian Vultures to analyse parental care investment. We collected data on nine different behavioural parameters/activities per sex, which were recorded throughout the entire breeding period. Variation in parental investment was analysed using generalized linear mixed models.

Results: Females invested more effort in incubation/brooding (61.45% for females and 31.54% for males) and egg turning (0.45?events/h for females and 0.37?events/h for males) while males contributed more to nest material delivery to the nest (0.67?deliveries/h for males and 0.14?deliveries/h for females). Conversely, both sexes invested the same effort in nestling attendance (21.89% for females and 21.21% for males) and food provisioning (0.28?items/h for females and 0.25?items/h for males). Furthermore, parental investment was not affected by weather, especially during critical moments such as incubation/brooding, however, changeover rate was positively related to temperature.

Conclusion: Our results suggest that, in the Egyptian Vulture, one sex is not entirely responsible for a particular task and the compensatory effort of the other mate is required. Finally, our findings indicate that major events such as incubation onset and hatching caused important shifts in the patterns of parental investment.  相似文献   

3.
In all comparative analyses, humans always fall on the borderline between obligate monogamy and polygamy. Here, we use behavioural indices (sociosexuality) and anatomical indices (prenatal testosterone exposure indexed by 2D : 4D digit ratio) from three human populations to show that this may be because there are two distinct phenotypes in both sexes. While males are more promiscuous and display higher prenatal testosterone exposure than females overall, our analyses also suggest that the within-sex variation of these variables is best described by two underlying mixture models, suggesting the presence of two phenotypes with a monogamous/promiscuous ratio that slightly favours monogamy in females and promiscuity in males. The presence of two phenotypes implies that mating strategy might be under complex frequency-dependent selection.  相似文献   

4.
The evolution of avian parental care   总被引:4,自引:0,他引:4  
A stage model traces key behavioural tactics and life-history traits that are involved in the transition from promiscuity with no parental care, the mating system that typifies reptiles, to that typical of most birds, social monogamy with biparental care. In stage I, females assumed increasing parental investment in precocial young, female choice of mates increased, female-biased mating dispersal evolved and population sex ratios became male biased. In stage II, consortships between mating partners allowed males to attract rare social mates, provided a mechanism for paternity assessment and increased female ability to assess mate quality. In stage III, relative female scarcity enabled females to demand parental investment contributions from males having some paternity certainty. This innovation was facilitated by the nature of avian parental care; i.e. most care-giving activities can be adopted in small units. Moreover, the initial cost of care giving to males was small compared with its benefit to females. Males, however, tended to decline to assume non-partitionable, risky, or relatively costly parental activities. In stage IV, altriciality coevolved with increasing biparental care, resulting in social monogamy. Approaches for testing behavioural hypotheses are suggested.  相似文献   

5.
When females choose a mate among a group of signaling males concentrated in a small area, a male's mating success is often determined not only by his absolute attractiveness but by the attractiveness of his neighbors as well. Multivariate analyses of sexual selection measurements based on absolute values of predictor variables are then misleading, because such analyses assume that the fitness of a given individual is not influenced by others. We addressed this problem of relative fitness in sexual selection by developing two adjustments of the predictor variables in the multivariate analyses by including group means in addition to absolute values and by using relative values, deviations from group means. In the lesser wax moth, Achroia grisella (Lepidoptera: Pyralidae), aggregated males produce ultrasonic signals attractive to females in the vicinity of honey bee colonies. Playback experiments showed that females prefer signals whose pulses are louder, longer, delivered at a faster rate, and include lengthy silent gaps within pulse pairs (long asynchrony intervals). To measure sexual selection on ultrasonic signals, attractiveness was assessed by observing the number of females orienting toward given males in four-choice trials. The various signal characters of the males were computed from ultrasound recordings. Multivariate regression and nonparametric analyses revealed that peak amplitude, asynchrony interval, and pulse rate were the direct targets of selection. Nonlinear stabilizing and correlational selection were also detected. Comparisons of results from multivariate analyses based on absolute values and on the two relative adjustments indicated that the quality of a four-male group did not affect the strength or direction of linear selection but changed the strength of nonlinear selection. Both relative adjustments improved the prediction of male attractiveness. Three-dimensional surface plots generated by the nonparametric regression analyses showed that attractiveness increased monotonically with any combination of the signal characters. This graphical technique also showed that female choice in A. grisella was based on a relative, as opposed to a threshold, decision rule. Overall, male attractiveness for the population remained consistent between testing days. However, attractiveness values for some individual males changed between successive testing days. In these cases, the change in attractiveness was related only to the change in peak amplitude.  相似文献   

6.
We studied the cranial postnatal ontogeny of Otaria byronia in order to detect sexual dimorphism in allometric terms, analyzing the rate of growth of functional variables linked to specific capacities as bite and head movements. We used 20 linear measurements to estimate allometric growth applying bivariate and multivariate analyses in females and males separately. Males were also analyzed in two partitioned subsets considering non-adult and adult stages, when the dimorphism is accentuated in order to reach optimal performance for intra-sexual competition. In the comparison of the employed techniques, we detected an empirical relationship between our multivariate results and the ordinary least square bivariate analysis. The quantitative analyses revealed different ontogenetic trajectories between non-adult and adult males in most variables, suggesting that the adult skull is not a scaled version of subadult skull. For instance, variables related with longitudinal dimensions decreased their allometric coefficients when the adult stage was reached, whereas those related with breadth or vertical dimensions increased their values. In adult males this could indicate that skull breadth and height are more important than longitudinal growth, relative to overall skull size. Conversely, inter-sexual comparisons showed that females and non-adult males shared similar ontogenetic growth trends, including more allometric trends than did males along their own ontogenetic trajectory. In general, adult males exhibited higher allometric coefficients than non-adult males in variables associated with bite and sexual behavior, whereas in comparison to females the latter showed higher coefficients values in these variables. Such patterns indicate a complex mode of growth in males beyond the growth extension, and are in partial agreement with changes previously reported for this and other species in the family Otariidae.  相似文献   

7.
Explaining the evolution of male care has proved difficult. Recent theory predicts that female promiscuity and sexual selection on males inherently disfavour male care. In sharp contrast to these expectations, male-only care is often found in species with high extra-pair paternity and striking variation in mating success, where current theory predicts female-only care. Using a model that examines the coevolution of male care, female care and female choice; I show that inter-sexual selection can drive the evolution of male care when females are able to bias mating or paternity towards parental males. Surprisingly, female choice for parental males allows male care to evolve despite low relatedness between the male and the offspring in his care. These results imply that predicting how sexual selection affects parental care evolution will require further understanding of why females, in many species, either do not prefer or cannot favour males that provide care.  相似文献   

8.
《Anthrozo?s》2013,26(4):306-319
Abstract

Sex differences in attitudes toward the use of animals have been reported in previous research. This study examines sex differences in the levels of, and the interrelations among, three potential antecedents of attitudes toward animal use: caring value orientation, pet care experience and attachment to pets. Path analysis showed that pet care experience, through attachment to pets, accounted for a significant portion of variance in animal use attitudes in both males and females. Caring value orientation was directly linked to animal use attitudes in females, but in males, caring value orientation affected attachment to pets, which in turn impacted on animal use attitudes. Results are discussed in terms of Gilligan's theory of socialization.  相似文献   

9.
Abstract

Relatively little is known about the motivational antecedents to the use of assisted reproductive technology (ART). In this paper we measure the fertility motivations of infertile couples who are considering the use of ART, using an established instrument, the Childbearing Questionnaire (CBQ). Our sample consists of 214 men and 216 women who were interviewed at home after an initial screening for ART but before making a final decision. We conducted two sets of analyses with the obtained data. In one set, we compared the scores on scales and subscales of the CBQ for the males and females in our sample with the scores for males and females from a comparable normative sample. For these analyses we first examined sample and gender differences with a four‐group analysis of variance. We then conducted a series of linear models that included background characteristics as covariates and interactions between sample, gender, and age and between those three variables and the background characteristics. The results showed the expected higher positive and lower negative motivations in the ART sample and a significant effect on positive motivations of the interaction between sample and age. In the second set of analyses, we developed several new subscales relevant to facets of the desire for a child that appear to be important in ART decision‐making. These facets include the desire to be genetically related to the child and the desire to experience pregnancy and childbirth. A third facet, the desire for parenthood, is already well covered by the existing subscales. The results showed the new subscales to have satisfactory reliability and validity. The results also showed that the original and new subscales predicted the three facets of the desire for a child in a multivariate context We conclude with a general discussion of the way our findings relate both to ART decision‐making and to further research on the motivations that drive it.  相似文献   

10.
Parasite-mediated sexual selection may arise as a consequence of 1) females avoiding mates with directly transmitted parasites, 2) females choosing less-parasitized males that provide parental care of superior quality, or 3) females choosing males with few parasites in order to obtain genes for parasite resistance in their offspring. Studies of specific host-parasite systems and comparative analyses have revealed both supportive and conflicting evidence for these hypotheses. A meta-analysis of the available evidence revealed a negative relationship between parasite load and the expression of male secondary sexual characters. Experimental studies yielded more strongly negative relationships than observations did, and the relationships were more strongly negative for ectoparasites than for endoparasites. There was no significant difference in the magnitude of the negative effect for species with and without male parental care, or between behavioral and morphological secondary sexual characters. There was a significant difference between studies based on host immune function and those based on parasite loads, with stronger effects for measures of immune function, suggesting that the many negative results from previous analyses of parasite-mediated sexual selection may be explained because relatively benign parasites were studied. The multivariate analyses demonstrating strong effect sizes of immune function in relation to the expression of secondary sexual characters, and for species with male parental care as compared to those without, suggest that parasite resistance may be a general determinant of parasite-mediated sexual selection.  相似文献   

11.
《Gender Medicine》2012,9(2):112-120
BackgroundFrequency of pretreatment methamphetamine (MA) use is an important predictor of outcomes of treatment for MA dependence. Preclinical studies suggest females self-administer more MA than males, but few clinical studies have examined potential sex differences in the frequency of MA use. Estrogen increases expression of brain-derived neurotrophic factor (BDNF), which has effects on MA-induced striatal dopamine release and protects against MA-induced neurotoxicity.ObjectiveWe examined potential effects of sex, the Val66Met polymorphism in BDNF, and their interaction on frequency of MA use among 60 Caucasian MA-dependent volunteers screening for a clinical trial.MethodsData was taken from 60 Caucasian MA-dependent volunteers screening for a clinical trial.ResultsFemales reported significantly more pretreatment days with MA use in the past 30 days than males. There was a significant interaction between sex and BDNF Val66Met, with the highest frequency of MA use among females with Val/Val genotype.ConclusionsThese results, although preliminary, add to the literature documenting sexual dimorphism in response to stimulants, including MA, and suggest a potential biological mechanism involving BDNF that might contribute to these differences. Additional research characterizing the biological basis of altered response to MA among females is warranted.  相似文献   

12.
A costs-benefits approach has frequently been used to understand the evolutionary origin and maintenance of promiscuity in animal populations. Recent meta-analyses suggest that direct costs to unfaithful females outweigh indirect benefits from infidelity in socially monogamous songbirds, suggesting that in this taxa, extrapair fertilization (EPF) evolved primarily as a self-interest male tactic. Here we present results of comparative analysis to show that standardized selection gradients acting against female infidelity (direct costs of promiscuity) explain variation in EPF rates at an interspecific level in passerines. This result confirms that costs to females resulting from reduced parental care from cheated males constrain promiscuity in this group. Our data indicate that females exert resistance over EPFs when the costs of infidelity are high and, conversely, that the rate of EPFs increases when selection on females to defend themselves against EPF attempts by males is weak and costs of infidelity are low.  相似文献   

13.
Synopsis Mating success of males and its correlates were investigated in a natural population of the polygynous fluvial sculpinCottus nozawae. Furthermore, the female mate preference of this species was examined experimentally under alternative conditions for mating in a stream. The mating success of individual males (the number of females with which a male mated) ranged between 0 and 8 with a mean of 2.41 in 1983 and 2.52 in 1989, in a population of which the sex ratio was about 1 : 2 in both years, skewed toward females. Mainly due to the excess of nests without egg masses and the few nests with one egg mass, the distribution of male mating success did not fit a Poisson distribution, indicating its non-randomness. Male mating success was not correlated either with the size of the nest rocks or with the male size, suggesting that these two variables are not determinants of mating success. The mate choice experiments demonstrated that females of this species more frequently chose smaller males as mates whose nests already contained eggs than large males without eggs. Additionally, an analysis of stomach contents of guarding males suggested that the parental males ate their own eggs during egg guarding (filial-cannibalism). Based on these results and on a comparison of reproductive characteristics with congeneric species, it is suggested that one of the most important determinants for female mate choice inCottus species may be whether or not parental males are filial egg cannibals.  相似文献   

14.
We studied the effect of mating frequency on female longevity and fecundity in the mite Caloglyphus berlesei. We tested the hypothesis that high promiscuity is selected for in this species because females receive nutrients during copulation. Females were constantly exposed to either one or four males and fed either a standard or poor diet. The prediction that frequent mating benefits females was not confirmed. On the contrary, females kept with four males had significantly lower longevity on both diets and on the standard diet they also had decreased fecundity compared to females exposed to one male. On the poor diet the number of males had no significant effect on fecundity. Thus, increased mating frequency had a detrimental effect on female fitness.  相似文献   

15.
In cooperative breeders, the tension between the opposing forces of kin selection and kin competition is at its most severe. Although philopatry facilitates kin selection, it also increases the risk of inbreeding. When dispersal is limited, extra-pair paternity might be an important mechanism to avoid inbreeding, but evidence for this is equivocal. The red-winged fairy-wren is part of a genus of cooperative breeders with extreme levels of promiscuity and male philopatry, but is unique in that females are also strongly philopatric. Here, we test the hypothesis that promiscuity is an important inbreeding avoidance mechanism when both sexes are philopatric. Levels of extra-pair paternity were substantial (70% of broods), but did not arise through females mating with their helpers, but via extra-group mating. Offspring were more likely to be sired by extra-pair males when the social pair was closely related, and these extra-pair males were genetically less similar to the female than the social male and thus, inbreeding is avoided through extra-pair mating. Females were consistent in their choice of the extra-pair sire over time and preferred early moulting males. Despite neighbouring males often being close kin, they sired 37% of extra-pair offspring. However, females that gained paternity from neighbours were typically less related to them than females that gained paternity further away. Our study is the first to suggest that mating with both closely related social partners and neighbours is avoided. Such sophistication in inbreeding avoidance strategies is remarkable, as the extreme levels of promiscuity imply that social context may provide little cue to relatedness.  相似文献   

16.
It is generally believed that level of paternity (the proportion of zygotes in a brood that were fertilized by the male providing parental care) has an important role in the evolution of parental care. We have used population genetics models to investigate this role. The models indicate that only in mating systems where a parental male “sacrifices” promiscous matings can paternity influence the evolution of male parental care. This is because level of paternity can reflect the number of opportunities for these promiscuous fertilizations. For example, high paternity can mean few opportunities and therefore a low cost for paternal care.Certain behaviors may preadapt a species for the evolution of male parental care because they decrease the costs of providing care. For example, in fish species where male care has evolved from spawning territories, the very establishment of territories may have precluded males from gaining promiscuous matings, thereby eliminating the promiscuity costs and facilitating the evolution of care. Without a promiscuity cost, level of paternity will not have influenced the evolution of male care in fishes.Because paternity has limited influence in the evolution of male care, differences in reliability of parentage between males and females are unlikely to explain the prevalence of female care. Our analysis suggests that paternity differences between species cannot serve as a general explanation for the observed patterns of parental care behavior.  相似文献   

17.
Sexually transmitted diseases (STDs) are known to exist in wild and domesticated animals, but little is know about behavioural defences that animals use to reduce the risk of acquiring STDs. Using comparative data and a phylogeny of primates, I investigated whether behaviours hypothesized to reduce STD transmission are correlated with measures of STD risk involving mating promiscuity and life-history traits. Comparative tests revealed no support for genital inspection as a means to identify and avoid infected individuals with genital inspection was performed more commonly by males than females and uncorrelated with mating promiscuity. Primate species characterized by increased promiscuity were not more likely to display genital self-grooming following mating. Similarly, males and females of these species were not more likely to urinate immediately after mating, counter to suggestions that urination flushes microorganisms from the urethra and surrounding genital areas. Finally, monogamy was not correlated with a slow life history, which differs from predictions that monogamy is a response to increased STD risk in long-lived animals. Tests involving monogamy remained unsupported after controlling for potentially confounding variables, and all tests yielded similar results in phylogenetic and nonphylogenetic tests. Few results were significant even before controlling statistically for multiple comparisons, but nonsignificance was unlikely due to low statistical power or poor data quality in all tests. Instead, the comparative patterns were consistent with theoretical models showing that precopulatory behavioural defences to STDs, such as mate choice, are unlikely to be fully effective. In addition, many putative behavioural defences to STDs in primates entail substantial fitness costs in terms of reproductive output, offspring quality and infanticide avoidance. Copyright 2003 Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour.   相似文献   

18.
Several competing hypotheses have been put forward to explain why females of many species mate preferentially with males possessing the most conspicuous signals (e.g., ornaments, displays, or songs). We performed a laboratory experiment using two species of poison frogs, Dendrobates leucomelas and Epipedobates tricolor, to test the hypothesis that male calling performance is an honest indicator of parental quality. Our analyses are based on data from behavioral observations of mating activities of captive-reared individuals (and their offspring) that were housed in terraria for four consecutive breeding seasons. Male mating success increased with male calling rate and chirp duration in both species, suggesting that females preferred males with more elaborate calls. Because calling performance improved with age in D. leucomelas, female poison frogs that prefer males with more elaborate calls in the wild may end up mating with older males that have already proven their ability to survive. Females that mated with good callers obtained higher quality offspring. Eggs fertilized by males with high calling rates and long chirp durations had higher hatching success and produced tadpoles that were more likely to metamorphose into surviving frogs. As a consequence, females that mated with males with high calling performance obtained more surviving offspring per egg, compared to females that mated with poor callers. Collectively, our findings comply with the notion that female poison frogs prefer to mate with good callers because calling performance is a reliable predictor of offspring quality. The possible influence of maternal allocation and reasons for the strong effect size compared to previous studies are discussed.  相似文献   

19.
We investigated the role that courtship and aggressive interactions may have for the maintenance of reproductive isolation betweenDrosophila silvestris andD. heteroneura. We examined the behavioral bases of reproductive isolation between the parental species and we examined the courtship success of each sex of both reciprocal F1 hybrids when paired with the parental species. We found reduced copulation success among heterotypic parental pairs compared to homotypic pairs, which was primarily due to the lack of courtship initiation betweenD. silvestris males andD. heteroneura females. When hybrid males from both reciprocal crosses were paired with parental females their copulation successes were not significantly different from that of parental males. In contrast, hybrid females from both crosses had reduced copulation success withD. silvestris males, which in turn was primarily due to a reduced success of reaching later stages of courtship. The time spent in copulation by hybrid males was intermediate between the two parental males. We studied aggression by observing the interactions of males of heterotypic pairs, both between the parental species and between the hybrids and parental males. A lack of aggressive interactions betweenD. silvestris males andD. heteroneura males in addition to the lack of courtship suggests thatD. silvestris males do not respond toD. heteroneura individuals of either sex. Hybrid males were equally successful in winning fights with bothD. silvestris andD. heteroneura males. These results indicate that the behavioral isolation betweenD. silvestris andD. heteroneura may be largely a consequence of the earliest stages of interactions. The two species may differ either in activity levels or in morphological or chemical traits that are important for species and mate recognition. The relatively high copulation and aggressive success of hybrids indicates that sexual selection against hybrids alone is unlikely to be a sufficient force to reduce gene flow and maintain species distinctions.  相似文献   

20.
We documented male and female parental roles of a monogamous fish, the spotted tilapia, Tilapia mariae, in channelized rivers in southern Florida, where this species dominated the fish fauna within 10 years of their introduction. Clearly differentiated parental roles existed between males and females, with females performing nearly all tending of embryos and most tending of free embryos. After young became free-swimming and left the nest, however, males took over primary tending of the school of young while the female patrolled the perimeter of the school and performed nearly all chases directed at predators. Male and female T. mariae also traded off vigilance and feeding, and showed a high degree of intrapair coordination. Experimental removal of one or both parents had major effects on parental behavior and brood survival and integrity. Solitary females took on a parental role intermediate between that of the male and female of a pair. Untended broods were attacked by predators and scattered into aquatic vegetation, and were not observed to reform. Under dense nesting conditions we observed adoption of broods, group rearing of free-swimming young and the presence of non-breeder satellites sharing and defending a territory with breeders. This highly complex parental care may have allowed T. mariae to invade fish communities dominated by uniparental centrarchids, as well as allowing them to use disturbed habitats such as channelized rivers that are of poor quality for nesting and rearing offspring.  相似文献   

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