Eavesdropping and signal matching in visual courtship displays of spiders

Eavesdropping on communication is widespread among animals, e.g. bystanders observing male–male contests, female mate choice copying and predator detection of prey cues. Some animals also exhibit signal matching, e.g. overlapping of competitors' acoustic signals in aggressive interactions. Fewer studies have examined male eavesdropping on conspecific courtship, although males could increase mating success by attending to others' behaviour and displaying whenever courtship is detected. In this study, we show that field-experienced male Schizocosa ocreata wolf spiders exhibit eavesdropping and signal matching when exposed to video playback of courting male conspecifics. Male spiders had longer bouts of interaction with a courting male stimulus, and more bouts of courtship signalling during and after the presence of a male on the video screen. Rates of courtship (leg tapping) displayed by individual focal males were correlated with the rates of the video exemplar to which they were exposed. These findings suggest male wolf spiders might gain information by eavesdropping on conspecific courtship and adjust performance to match that of rivals. This represents a novel finding, as these behaviours have previously been seen primarily among vertebrates.

Sex recognition in surface and cave dwelling male Atlantic mollies Poecilia mexicana (Poeciliidae, Teleostei)

Animals colonizing lightless subterranean habitats can no longer rely on visual signals to find mating partners. In the present study, we investigated the ability of males to recognize females in two surface and a cave dwelling population of a livebearing fish, Poecilia mexicana. In surface populations males discriminated between sexes with visual plus non-visual cues available and with visual stimuli only. In the cave form the ability to discriminate with solely visual stimuli is lacking. In all three populations, males did not recognize females in darkness (infrared observations), suggesting that sex recognition via far-field communication is lacking in surface and cave dwelling P.mexicana. Different preferences in large and small males to stay near a female or a male stimulus fish probably reflect differences concerning a trade-off between sexual and aggressive behaviour.

On the Role of Emotional Traits in Impression Formation

280 Italian undergraduates (90 men and 190 women), ages 18 to 30 years, rated a warm, cold, jealous, or envious stimulus person on 15 7-point semantic differential scales. Varying the sex of the stimulus person, 8 different versions of the description were obtained. Factor analysis, carried out to identify a smaller set of non-redundant dimensions, yielded three factors. A multivariate analysis of variance, 4 (warm, cold, jealous, envious) × 2 (male stimulus person, female stimulus person) × 2 (male respondents, female respondents), indicated significant effects for the variable “trait” on the first and second factors, an interaction between the sex of the stimulus person and the sex of the respondent on the first factor, and an effect for the sex of the respondent on the second factor. The traits “envious” and “jealous” acted as central qualities, and the sex of the stimulus person and of the respondent played an important role in impression formation. Further implications of the finding were discussed.

Function of the Song and Song Repertoire in the European Starling (Sturnus Vulgaris) : an Aviary Experiment

We confronted individually-caged male European starlings, Sturnus vulgaris, with conspecifics of both sexes in order to study singing behaviour during intrasexual and intersexual encounters. Males spent more time at the nestbox, sang more songs and more song types during female presentations than during control periods (observation periods with no conspecifics). Males also sang more songs in the nestbox and flew more to the nestbox with green nest material. During male presentations, only the time spent at the nestbox and the carrying of nest material increased significantly. Males spent more time at the nestbox, sang more songs and more song types in response to a female stimulus than to a male stimulus. Males also sang more songs in the nestbox and flew more to the nestbox with nest material during female than during male presentations. These results suggest that the song and song repertoire of male starlings serve primarily an intersexual rather than an intrasexual function. However, in contrast to a previous study, our results suggest that singing also serves as an intrasexual signal to deter rivals at close encounter. We also tested the hypothesis that the 'whistles' and the 'warbling song' have separate intrasexual and intersexual functions, as has been suggested in the literature. We found no evidence for a specialized intrasexual function of the whistles nor for a specialized intersexual function of the warbling song. From this study it also appears that variations in the size of the aviary can modify the behavioural responses of starling males. New information with regard to the use of green nest material by male starlings is given.

Attribution of Feminine and Masculine Traits to Opposite-Sex Dyads

Descriptions of achieving female and male dyads in different relationships were presented to subjects and rated using masculine and feminine stereotypic traits. The relationship between the dyads varied in level of involvement—no relationship between them, acquainted, dating and married. Both the male and female stimulus-persons were rated more masculine when they were successful than when they were unsuccessful. Attributions of masculine traits to the “out-of-role,” achieving, female stimulus-person were made on the basis of internal factors, whereas attributions to the “in-role” achieving, male stimulus-person were made on the basis of both internal and external factors. In ratings made by men, the woman's achievement level affected the man's masculinity and self-esteem when the couple was dating—they attributed lower masculinity and lower self-esteem to the male stimulus-person when the woman was a success than when she was a failure. A nonstereotypic description of the couple, in which the woman was first and the man second, increased the masculinity and decreased the femininity attributed to both of them.

Female-Male versus Male-Female: Does the Order Affect Stereotyped Trait Attributions?

The traditional male-female ordering found in American society may reinforce stereotypic attributions of traits to the two sexes. This hypothesis was tested by having female and male college students rate female and male stimulus persons on 12 traits after reading story paragraphs that varied the sex, the ages of the stimulus persons, and the order of presenting the stimulus persons. When the male was tested before the female stimulus person (traditional order), each sex received more favorable ratings on traits usually considered socially desirable for the sex. When the female was tested before the male (counter traditional order), female stimulus persons continued to receive more favorable ratings on traits usually associated with females than the male stimulus persons, but they also received more favorable ratings on traits usually associated with males. Trait attributions also differed for the four age groups tested.

Sex Domination of Occupations and the Tendencies to Approach and Avoid Success and Failure

To test a theory that approach and avoidance imagery would be associated with both success and failure, female and male college students wrote stories to sentence cues. The sentence cues described a female or male stimulus person as succeeding or failing in one of six occupations. Two of the occupations were dominated by females, two by males, and two were approximately equal in sex domination. The imagery content of the stories yielded independent evidence of success-approach, success-avoidance, failure-approach, and failure-avoidance imagery. Success-approach and failure-avoidance imagery increased as the current male domination of the occupation increased; failure-approach imagery increased as the current female domination of the occupation increased. Success-approach imagery appeared more often in stories written by female respondents; success-avoidance imagery appeared more often in stories written by male respondents. The results were consistent with an achievement model that provides for approach and avoidance tendencies to success and failure. Differential results for the respondents of the two sexes are theoretically attributable to different weightings of the four motives mediated by the anticipated consequences of success and failure.

Sexism and Sexual Problems: Societal Censure of the Sexually Troubled Male

This experiment tested the hypothesis that the sexually troubled male is perceived as having deviated from a fundamental male-role expectation and will therefore receive a more negative evaluation of mental health. A contrived verbatim account of an interviewee's reporting either personal sexual dissatisfaction or a partner's dissatisfaction was presented to 72 male and 72 female college students. The sex of the target was manipulated by identifying the interviewee as either Allen or Alice. As predicted, the male interviewee received poorer scores on the Psychological Effectiveness Scale and greater perceived likelihood of psychological disturbance. The male stimulus person was also seen as having a greater need for psychotherapy and less chance for attaining happiness in life. The results consistently showed that these negative evaluations of the male target were made by male, but not female, subjects. Discussion focused on this self-imposed psychological pressure for adequate male sexual functioning as a harmful role stereotype.

Additional Evidence for Veridicality of Perceptions Based on Physiognomic Cues

This study was designed to determine whether veridical interpersonal perceptions can be formed on the basis of physiognomic cues. 21 male and female college students attempted to identify the correct social category [honor student, active or inactive in extracurricular events, and beauty queen (for female stimulus persons) or athlete (for male stimulus persons)] of 44 photographed male and female stimulus persons. Results demonstrated considerable veridicality, especially by male judges and of stimulus persons occupying categories which imply physical attributes.