Sexual-discrimination learning in male Japanese quail (Coturnix coturnix japonica)

We investigated how male Japanese quail (Coturnix coturnix japonica) learn through extensive social and sexual experience to discriminate between male and female conspecifics. Opportunity for heterosexual copulation was important for this learning, but even extensive copulatory opportunity was not sufficient to produce a sexual discrimination; subjects also required exposure to other males. Exposure to females after copulatory opportunity did not produce a sexual discrimination but facilitated its acquisition. Time or exposure to only the visual features of male birds (provided by taxidermic models) after copulatory opportunity did not result in differential responding to male and female conspecifics. Finally, presenting stimulus birds one at a time proved to be a more sensitive test of sexual-discrimination learning than presenting two stimulus birds at the same time. The results indicate that sexual-discrimination learning is similar to conventional associative learning.     

Sensitization of escape in female Betta splendens

Following 1 day of cohabitation with a male, female Siamese fighting fish showed heightened escape from male conspecifics (enclosed behind glass). Escape from males was general in that no particular male stimulus was required to provoke female escape. However, female conspecifics remained relatively attractive following exposure to a male. Tactile stimulation of females by males (biting, perhaps) plays some role and may be required in sensitizing females' escape from males. © 1996 Wiley-Liss, Inc.     

Learning to discriminate the sex of conspecifics in male Japanese quail (Coturnix coturnix japonica): tests of "biological constraints"

Male Japanese quail learn to approach and remain near female, but not male, quail if they are allowed to copulate with female quail and receive noncopulatory exposures to males. The generality of the mechanisms involved in this type of discrimination learning was investigated in the present study. In Experiment 1, Ss learned to spend more time near initially unfamiliar blonde quail than familiar brown female or male quail as a result of being allowed to copulate with the blonde, but not the brown, quail. In Experiment 2, Ss learned to respond more to nonreproductive male as compared with female quail as a result of being allowed to copulate with the males, but not with the females. The experiments provided some evidence of a bias favoring responding to females independent of copulatory reinforcement contingencies. However, the results also indicated remarkable plasticity of discrimination learning about species-specific sexual stimuli.     

Sex differences in discrimination reversal learning in the guppy

In several mammalian and avian species, females show a higher performance than males in tasks requiring cognitive flexibility such as the discrimination reversal learning. A recent study showed that female guppies are twice as efficient as males in a reversal learning task involving yellow–red discrimination, suggesting a higher cognitive flexibility in female guppies. However, the possibility exists that the superior performance exhibited by females does not reflect a general sex difference in cognitive abilities, but instead, is confined to colour discrimination tasks. To address this issue, we compared male and female guppies in two different discrimination reversal learning tasks and we performed a meta-analysis of these experiments and the previous one involving colour discrimination. In the first experiment of this study, guppies were tested in a task requiring them to learn to select the correct arm of a T-maze in order to rejoin a group of conspecifics. In experiment 2, guppies were observed in a numerical task requiring them to discriminate between 5 and 10 dots in order to obtain a food reward. Although females outperformed males in one condition of the T-maze, we did not find any clear evidence of females’ greater reversal learning performance in either experiment. However, the meta-analysis of the three experiments supported the hypothesis of females’ greater reversal learning ability. Our data do not completely exclude the idea that female guppies have a generally higher cognitive flexibility than males; however, they suggest that the size of this sex difference might depend on the task.     

Sensory cues that elicit ultrasonic vocalizations in female rats (Rattus norvegicus)

Female rats emit ultrasonic vocalizations during copulation. Female vocalizations are associated with darting and other proceptive behavior. In addition, females frequently call while approaching the male. A series of experiments was undertaken to determine whether female rats emit ultrasonic vocalizations in response to other rats or to their odors. Females were exposed either to bedding soiled by males or females or to devocalized conspecifics separated from the subject by a barrier. Females vocalized more to male cues than to female cues, regardless of whether the odor cues were from soiled bedding or from a devocalized conspecific. In addition, subjects vocalized more when presented with a devocalized female rather than a neutral stimulus. Furthermore, devocalized adult males, separated by a barrier, were more effective than either devocalized castrated or juvenile males in eliciting vocalizations; in turn, castrates and juveniles were more effective than neutral stimuli. Female calling was likely induced by odors from the male. In one experiment, the female subject was positioned in such a way that she could neither see or touch the stimulus male. Presentation of tape-recorded male vocalizations did not affect calling by the female. Vocalizations emitted by females in response to male odors may attract males or may facilitate subsequent copulatory behavior by the male.     

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.     

Ultrasonic vocalizing by adult female mice (Mus musculus)

Though an extensive body of literature exists concerning the emission of 70-kHz ultrasonic vocalizations by adult male mice (Mus musculus), almost nothing is known about the ultrasonic vocalizing of adult females. A series of five experiments was conducted to examine adult female mouse ultrasound emission. Results indicated female ultrasonic vocalizing to be typically displayed among female mouse dyads and comparable to the ultrasonic vocalizing levels obtained among male-female pairs. Genotypically based variations in the production of ultrasounds by females were also noted. Like male mice, socially naive females readily ultrasonically vocalized to anesthetized female conspecifics and rarely vocalized to anesthetized males. Unlike males, socially experienced females emitted few ultrasounds to either female urine or female-soiled cage shavings. Although social experience served to increase the ultrasound emission of male mice to female sex cues, the production of ultrasounds by females to these cues was decreased by social experience. Implications with regard to the existence of a behavioral/functional sexual dimorphism in adult mouse ultrasonic vocalizing are discussed.     

Fer cryin' out loud — There is a sex difference

Self-reported crying behavior of 307 female and 285 male university students was studied. Female subjects reported crying significantly more frequently and intensely than did male subjects. In all six interpersonal situations female subjects indicated greater likelihood of crying than did male subjects. Significantly more females than males indicated they would cry in 17 of 20 stimulus situations. Where there were significant sex differences in reporting of postcrying affect, a higher percentage of females than of males indicated that they experienced the feelings described. The sample, with few exceptions, viewed females as crying more frequently than males. Despite these sex differences, many evidences of similarity between the sexes in crying behavior were found.An earlier version of this article was presented at the Western Psychological Association Meetings in San Diego, April 1979.     

Affiliation and aggression as related to gender in domestic chicks (Gallus gallus).

Social discrimination in male and female domestic chicks (Gallus gallus) was investigated by using (a) latencies of approach response, (b) simultaneous free choice, and (c) intersubject aggressive-pecking tests. In approach-response tests, females showed shorter latencies when tested with cagemates than when tested with strangers, whereas males showed shorter latencies when tested with strangers than when tested with cagemates. In simultaneous-choice tests, females spent more time near a cagemate, whereas males spent more time near a strange chick. In aggressive-pecking tests, both sexes pecked more at strangers than at cagemates; aggressive pecking at strangers, however, was higher in males than in females. It is argued that gender effects in social discrimination can be accounted for in terms of stronger social attachment in females and aggressive responses in males.     

Female meadow voles,Microtus pennsylvanicus,respond differently to the scent marks of multiple male conspecifics

Many nonhuman animals are capable of discriminating a group or entity containing more objects from one containing less of the same objects. The capacity for making judgments of numerousness may also allow individuals to discriminate between potential mates. Female meadow voles (Microtus pennsylvanicus) may use judgments of relative numerousness to distinguish between potential suitors by selecting males that signal their interest by depositing more scent marks relative to other males. We used a familiarization–discrimination paradigm in the absence of training to test the hypothesis that female voles will discriminate between the different numerosities of scent marks of two male conspecifics that are similar in features of their phenotype and quality. During the exposure phase, we presented female voles with different ratios of feces scent marks from two males. During the test phase, we presented females with a single, fresh fecal scent mark from each of the two male donors, whose marks they had previously encountered during the exposure phase. In both phases, females spent more time investigating the scent mark(s) of the male that deposited more scent marks than that of the male that deposited fewer scent marks provided the difference in the ratio of scent marks provided by the male donors in the exposure phase was ≥2. Our results are consistent with studies on a variety of taxa, suggesting that numerosity discriminations are evolutionarily ancient and spontaneously available to nonhuman animals and humans.     

Avoidance of relatively aggressive male Japanese Quail (Coturnix japonica) by sexually experienced conspecific females

Sexually experienced female Japanese quail (Coturnix japonica) that are offered a choice between 2 conspecific males previously observed engaging in an aggressive encounter prefer to affiliate with the less aggressive male. The authors determined whether this apparent preference for less aggressive males results from females approaching less aggressive individuals or avoiding more aggressive individuals. The authors found that females that had seen 2 males fight before choosing, in counterbalanced order, between each of them and a neutral stimulus were indifferent to less aggressive males but avoided more aggressive males. The results are consistent with the view that in species in which male courtship and mating are potentially harmful to females, females keep away from relatively aggressive males in order to avoid the physical punishment that can result from contact with them.     

Social preferences of developing guinea pigs (Cavia porcellus) from the preweaning to the periadolescent periods

Preference tests in a novel environment (Experiment 1) and unobtrusive observations in a specialized living environment (Experiment 2) examined the attractiveness of various classes of conspecifics for maturing guinea pigs (Cavia porcellus). It was found that (a). the young continued to remain near the mother well beyond weaning; (b). there was increased time spent with unrelated adult females, but not males, after weaning; (c). male and female offspring behaved similarly; and (d). littermates spent considerable time with each other. These results provide no evidence that guinea pigs approaching sexual maturity begin to associate preferentially with novel animals or potential breeding partners. Choices were largely predictable from earlier findings of the ability of various classes of conspecifics to reduce hypothalamic-pituitary-adrenal activity of the young.     

Sex roles and friendship patterns

The purpose of this study is to examine the relationships among sex, sex role orientation, and friendship. Based on the Bem Sex Role Inventory, 164 participants were categorized as either androgynous (17 males; 29 females), traditional (36 males; 39 females), or undifferentiated (26 males; 17 females) in their sex role orientation. Participants reported the number of close male and female friends, and responded to several questionnaires: interpersonal trust of male and female friends, communal and exchange orientations, affective and activity attributes associated with male and female friends, loneliness, and friendship satisfaction. Results indicate that close friends tended to be same sex, even though females had more close friends overall than did the males. Androgyny was related to characteristics that enhance the development and maintenance of close friendships, such as a communal orientation and positive conceptions of friends, while the undifferentiated orientation was related to less relationship enhancing orientations and a less rewarding interpersonal milieu. The study confirms that sex and sex role orientation are important factors in both quantitative and qualitative aspects of friendship during young adulthood.Portions of this paper were presented at the annual convention of the Southwestern Psychological Association, Houston, Texas, April 13, 1989. We appreciate the extensive help of an anonymous reviewer on earlier versions of this paper.     

Status versus warmth as determinants of sex differences in personal space

Previous studies indicate that females are allotted less personal space than males. In everyday situations, both warmth and low status may be confounded in women, thus obscuring the roles each may play in determining interpersonal distance. The present study manipulates sex, status (a professor or a student), and sociability (warm or cold) of a stimulus person independently of each other. Subjects were 40 male and 40 female students who were asked to form impressions of the stimulus person from a videotaped recording and a personal interview. Results indicate that males are given more space than females. Both status and sociability influence the amount of space that males are allotted, with the cold low-status male being allowed the most space. For females, the high-status woman was allowed more space than the low-status one, and sociability bore no relation to how close others came to her. These findings are discussed in relation to the previous studies on sex differences and personal space.     

The Effect of the Sexual Composition of a Group on Discrimination Against Women and Sex-Role Attitudes

This study examined discrimination against women and endorsement of sex-role attitudes as a function of sex composition of group and sex of subject. Undergraduates (116 female and 55 male) were placed in mixed-sex or all-women groups and administered a modification of the journal articles used by Goldberg (1968) and a Sex-Role Attitude Questionnaire developed by the author. Both females and males in the mixed-sex groups evaluated the female-authored articles less favorably than the identical male-authored articles. In contrast, subjects in the all-women groups did not show sex discrimination in their evaluations. Sex-typed appropriateness of the article topics was not an important variable mediating the devaluation of the female-authored articles. Female subjects in mixed-sex groups endorsed more profeminist ideas on the Sex-Role Attitude Questionnaire than did male subjects, and there was a nonsignificant trend for women in the all-women groups after reading female-authored articles to endorse more profeminist ideas than did the women in the mixed-sex groups or in the all-women groups after reading male-authored articles. Results suggest that participation in an all-women's group may elicit a more positive image of other women and contribute to more egalitarian perceptions and behaviors.     

Scent marking by male dwarf hamsters (Phodopus sungorus campbelli) in response to conspecific odors

Male hamsters (Phodopus sungorus campbelli) scent marked at greater frequencies in the presence of conspecific odor, either male or female, than in clean areas. Marking rates were not different between male and female odor conditions. In contrast, the pattern of investigation in response to conspecific odor did differ between the male and the female odor conditions. When male odors were used as stimuli, investigative sniffing increased at the scent marking sites but when female odors were used as stimuli investigative sniffing increased throughout the arena. Thus, male dwarf hamsters direct their scent marks at both male and female conspecifics, discriminate between male and female odor, and investigate in a different manner areas scent marked by males and females.     

女性对新异性事件加工的偏向:来自ERP的证据

采用修订后的oddball范式,结合ERP技术考察女性与男性在加工中性新异刺激时的差异。ERP结果表明,在早期已经出现新异性效应。在300-500ms内,新异刺激在男性和女性被试中都比标准刺激诱发了更大的LPC。在500-700ms内,新异刺激仅在女性被试中比标准刺激诱发更大的LPC,在男性被试中没有显著差异。这些结果表明男性和女性都对中性新异刺激表现出加工偏向,但是女性对其加工的时间比男性更长。这可能与女性容易对显著性(salient)的刺激进行沉思(rumination)相关。     

Sex differences in investigatory and grooming behaviors of laboratory rats (Rattus norvegicus) following exposure to novelty

Prior research suggested that during exposure to novel stimuli, rodent investigation and self-grooming behaviors may be sexually dimorphic and interact with ambient illumination. To test this notion we compared the behavior of adult male and female groups of Long-Evans hooded rats in normal room lighting (860 lx) and in very dim, red light (0.2 lx) following exposure to a novel juvenile conspecific. Illuminance level had little or no effect, but investigatory and subsequent self-grooming behaviors of males were substantially greater than those of females, and females engaged in greater ambulatory activity than did males. In a second experiment adult males and females were exposed to a novel inanimate object. No reliable sex differences were observed. We conclude that social novelty, as provided by exposure to a juvenile conspecific, stimulates greater investigation and postinvestigatory self-grooming than exposure to a novel inanimate object and that exposure to novel conspecifics presents a useful method for the investigation of sex differences, gonadal hormone effects, and interactions of hormones with neurotransmitter systems governing motor control systems.     

Females, but not males, show greater pupillary response to direct- than deviated-gaze faces

Under suitable conditions, pupillary dilation is a reliable index of processing activity. Pupil size was tracked in male and female observers following the presentation of face stimuli for an age-judgment task. The eyes on the faces were either directed towards the observer or deviated to the side. Pupil dilation accompanied processing of the faces, but female observers showed significantly more sustained pupil dilation when viewing direct- than deviated-gaze faces over the period 3 to 7 s after stimulus onset, regardless of stimulus sex. In contrast, male observers did not show a consistent pattern in response to either the gaze or sex of the face stimuli. These findings indicate a sex difference in the processing of gaze direction and suggest that females, but not males, apply increased effort to processing socially relevant (direct-gaze) than irrelevant (deviated-gaze) faces. They also demonstrate that pupillary measurement can potentially provide new insights into the processing of even visual input, provided reflexes are sufficiently controlled.     

Inseminated female mice (Mus musculus) investigate rather than avoid novel males that disrupt pregnancy, but sires protect pregnancy

Experiment 1 replicated the Bruce effect, showing pregnancy termination in CF1 strain female mice (Mus musculus) housed underneath novel heterogeneous strain (HS) males. In a 4-arm maze in Experiment 2, inseminated CF1 females approached novel HS males more often than CF1 sires or unfamiliar CF1 males. In Experiment 3, inseminated females showed random nesting sites when housed continuously underneath 4 compartments containing the sire, a novel CF1 male, a novel HS male, and no stimulus. In Experiment 4, when inseminated females were housed with or without the sire below novel HS males, the sire's presence decreased female interaction with novel males and mitigated the Bruce effect. Inseminated females do not reliably avoid males that disturb pregnancy unless the sire is immediately present.