Response of male and female Siberian hamsters towards pups

The influence of sex, reproductive maturity, and parental experience on the behavior of Siberian hamsters (Phodopus sungorus sungorus) toward strange pups was examined in this study. Immature, mature, or parentally experienced male and female Siberian hamsters were presented with 3- to 8-day-old pups. We recorded pup carrying during the initial 10 min, nesting with pups after 8 or 14 h, and attacking pups during the test period. Among inexperienced animals, more mature males attacked pups than did immature males or mature females. Parental experience significantly decreased pup attacks by males and increased nesting with pups by both males and females. Repeated testing did not modify the responses to pups. We conclude that in Siberian hamsters both caretaking and aggressive responses to pups may be shown by immature and mature animals of both sexes. Parental experience resulted in increased caretaking by males and females and decreased aggressive responses by males.     

Conflict behaviors toward same-sex and opposite-sex peers among male and female late adolescents

Differences between males and females in regard to conflict behaviors toward same-sex and opposite-sex peers were examined in a sample of 501 undergraduate university students (326 males, 175 females). They completed a one-page questionnaire containing the theoretical definitions of five conflict behaviors identified by Thomas (1976): competing, avoiding, accommodating, compromising, and collaborating. Students were asked to rate the extent to which they exhibit each of these conflict behaviors, on a 5-point Likert-type scale, separately for same-sex and opposite-sex peers. Results revealed that males reported more competing behavior toward same-sex peers than toward opposite-sex peers, and more avoiding behavior toward opposite-sex peers than toward same-sex peers. Males, compared to females, reported more accommodating behavior toward both same-sex and opposite-sex peers. These findings support the view that preferences regarding conflict behaviors are different for males and females, particularly as exhibited toward same-sex and opposite-sex peers.     

Social influences on parental and nonparental responses toward pups in virgin female prairie voles (Microtus ochrogaster)

Pair-bonded prairie voles (Microtus ochrogaster) are biparental after the birth of pups. However, whereas most adult virgin males are parental, most virgin females are not. In 6 experiments, influences on the parental behavior of virgin female prairie voles were examined. It was found that (a) young virgin females were more maternal than older females, (b) the postweaning sex ratio of cage-mates did not affect females' responses to pups, (c) females raised to adulthood with their parents and younger siblings present were highly parental, (d) 48-hr exposure to pups beginning at weaning increased some aspects of later maternal responding, (e) rearing to adulthood with the parents even in the absence of younger siblings also increased females' maternal responding, and (f) the increase was seen only if both parents were present. Continued parental presence promotes alloparental behavior, possibly important if daughters do not disperse from the natal nest.     

The Development and Sex-Related Use of Interruption Behavior

In this article the authors argue that claims of sex differences in interruption behavior should not be uncritically accepted as there are limitations in previous research that make such acceptance questionable. The frequency of interruption was examined over a portion of the early life span (Grades 4 and 9 and college). Twenty-minute structured conversations of 90 dyads (30 male, 30 female, and 30 mixed sex) were scored for four types of interruption, and both developmental and sex differences in interruption behavior were examined. Interruption frequency did not change over age or across dyads of different sex composition. Males did not interrupt any more than females did and females were interrupted by their partners as frequently as males were interrupted by theirs, with one exception: Grade 9females were interrupted more by their female partners. Interruptions were asymmetrically distributed in same-sex and opposite-sex dyads; however, the asymmetry in opposite-sex dyads was not predictablefrom sex of subject or sex of partner. That is, males did not interrupt females any more than females interrupted males. The authors conclude that wholesale acceptance of sex differences in interruption behavior is not warranted.     

The Effects of Sex of Subject and Sex of Partner on Interruptions

Sex differences in interruption behavior were examined using the Kraemer-Jacklin (1979) procedure to isolate and test the effects of sex of subject, sex of partner, and their interaction while controlling for between partner correlation. The results of the study were three. First, men did not interrupt more than women and women did not get interrupted more than men. Instead, there were more opposite-sex interruptions, both male-female and female-male, than same-sex interruptions, both female-female and male-male. Second, interruptions were asymmetrically distributed in both same-sex and opposite-sex dyads. However, in opposite-sex dyads males did not interrupt females more than females interrupted males. Third, women did not have less assertive behaviors interrupted; they did not interrupt less assertively, nor did they respond less assertively to interruptions.     

Gender and distributive justice: The influence of gender-related characteristics on allocations

The influence of dispositional and situational gender-related factors on the distributive justice behavior of males and females was examined in this research. Using the self-other allocation paradigm, traditional and andrognyous subjects outperformed traditional or androgynous opposite-sex co-workers (Experiment 1) or same-sex co-workers (Experiment 2). The task gender-linkage and the physical attractiveness of the opposite-sex co-workers were also considered. The results indicated that androgynous persons were more generous in their allocations and were less influenced by the gender-related characteristics of an opposite-sex co-workers than traditional persons. In same-sex dyads, males were more equitable than females and were uninfluenced by gender-related factors. Traditional, but not androgynous, females adjusted their allocation behavior according to the gender-linkage of the task, allocating more equitably on gender-congruent tasks than on gender-incongruent tasks. The significance of these findings to understanding sex differences in distributive justice behavior is discussed.     

Mate recognition by urine odors in the Mongolian gerbil (Meriones unguiculatus)

We examined the responses of male and female gerbils housed in opposite- or same-sex pairs to the urine odors from their cage-mate and those of an unfamiliar gerbil of the same sex. Gerbils housed in mated pairs spent more time investigating the odor of their partner. They also emitted more modulated ultrasonic vocalizations in the presence of their partner's odor than in the presence of the unfamiliar odor. Gerbils housed in same-sex pairs did not respond differentially to the odor of their cage-mate. There were sex differences in the frequency of ventral scent-marking and modulated vocalizations, with males showing more of these behaviors than females. The urine odor of the gerbil's mate can thus be discriminated from those of other gerbils. Recognition of individual odors may promote affiliative behavior and reduce aggression, thus playing an important role in pair maintenance in gerbils.     

Social mediation of puberty: an adaptive female strategy?

Females of two hamster species with contrasting degrees of gregariousness were tested for social influences on the timing of sexual maturation. When female dwarf hamsters (Phodopus sungorus campbelli), a gregarious species, were housed with an adult male at weaning, they began estrous cycles significantly earlier than when they were housed alone or with their family. Females housed with one or two female siblings at weaning matured significantly later than did all other females. Once mature, females housed with familiar males conceived later than did females housed with unfamiliar males. Rearing conditions also affected body weight; those housed with female siblings grew more slowly and attained a lower weight at 8 weeks of age than did females in all other groups. In contrast, when weanling female golden hamsters (Mesocricetus auratus), a solitary species, were housed with either an adult male, two female siblings, or alone, they did not differ in their rate of sexual maturation or growth. It is suggested that the degree to which social factors can accelerate or delay puberty is an adaptive characteristic and may be correlated with the degree of gregariousness of a species.     

Physical attractiveness and interpersonal influence

The relative success of influence attempts undertaken by attractive vs. unattractive fifth- and sixth-graders was investigated by giving subjects a monetary incentive contingent upon their influencing a peer's behavior. Compared to a control group which was not subject to peer pressure, three groups were successful: attractive males and attractive females with opposite-sex peers and unattractive males with same-sex peers. Attractive girls tended to be more successful than their unattractive counterparts in influence attempts directed toward peers of the opposite-sex. Unattractive males were more effective than attractive males with same-sex peers. Analysis of the influence strategies employed revealed markedly different styles of interpersonal influence, particularly between attractive males and attractive females. The former made considerably more influence attempts and were judged to be more persistent. This type of behavioral difference was not found for unattractive males compared to unattractive females.     

Short-term early exposure to pups alters infanticide in adulthood in male but not in female wild house mice (Mus domesticus)

Male and female wild house mice (Mus domesticus) were allowed to remain in the cage of their parents until 30-35 days of age. When a second litter was delivered, the first litter was exposed to the younger pups for 2-10 days. In adulthood the male and female mice that had been exposed to pups as juveniles and an additional group that had cohabitated with their parents for the same length of time but were not exposed to pups were tested for infanticidal behavior. The frequency of infanticide by the adult female mice was not significantly different (55% vs. 70%, respectively). In contrast, the adult males that were exposed to pups as juveniles were significantly less likely to kill young in adulthood when compared with males that were not similarly exposed (35% vs. 80%, respectively). These data further demonstrate the strong influence of experience on the expression of infanticide by male mice and its relative unimportance to the expression of female infanticide.     

Same-sex patterns and sex differences in the trust-value basis of children's friendship

Thirty-six children in fourth grade were required (a) to report the secret-sharing, secret-keeping, promise-making, and promise-keeping behaviors of classroom peers; and (b) to judge those classmates on trust and friendship. Teachers provided observations of the children's friendship interaction. Same-sex patterns were found in observed friendship, friendship ratings, trust, secrets shared, proportion of secrets kept, and promises made. These were less frequent/lower for opposite-sex peers than for same-sex peers. As expected, males tended to share fewer secrets with same-sex peers than did females. The expected associations were found among proportion of secrets kept, proportion of promises kept, trust, and rated or observed friendship in females but with one exception in males. The findings supported the conclusion that same-sex friendship patterns are maintained by same-sex trust patterns through (a) infrequent secret sharing with opposite-sex peers and (b) the perception that opposite-sex peers break secrets more frequently than same-sex peers. The findings also supported the conclusion that there are some sex differences in the intimacy/trust basis of friendship.     

Perspectives on self and other: Male-female differences in perceptions of communication behavior

Two studies were conducted to examine male-female differences in perceptions of subjects' own and their best-liked others' communication behavior. The results of the first study indicated that males and females hold relatively stereotypical views of their own communication behavior. Males perceived themselves as more controlling and detached, while females saw themselves as more nurturant and more dependent. The results from the second study indicated that the discriminating dimensions for the same-sex friendships of both males and females were attention-seeking and self-dramatizing communication behaviors. In an opposite-sex relationship, however, the discriminating communication behaviors for males and females were nurturance and dependency. The implications of these findings are discussed.Both authors would like to thank Edmund Kaminski, currently a doctoral candidate at Michigan State University, for his valuable assistance on this project.     

Person, situation, and person-by-situation interaction components in person perception

The hypothesis that people store situation and person-by-situation interaction information as well as trait information about one another's behavior was tested by administering modified S-R Inventories of Anxiousness and Hostility to 54 male and 59 female undergraduates. Subjects rated the strength of affect that would be evoked by a series of situations in the two same-sex college students whom they knew best, the best-known opposite-sex person, a casually known same-sex person, and the “average college student.” Indices were constructed to measure the extent of (a) perceived average differences among people (traits), (b)perceived average differences over situations, and (c) perceived person-by-situation interaction. Analyses of variance showed that: (a) the ratings of the two best-known same-sex persons and the best-known opposite-sex person contained more interactive information than did the ratings of a casually known person and (b) females perceived more situational variability in the behavior of their own sex than did males. The amount of perceived person-by-situation interaction did not differ as a function of sex of rater or affect to be rated. It was concluded that the naive psychologist, like many professional psychologists, is an interactionist.     

Effect of conspecific sex on aggression during pregnancy and lactation in golden hamsters

The effect of conspecific sex on maternal aggression in hamsters was determined by comparing the frequency of aggressive responses by dams continuously housed with either a virgin male or female cagemate during pregnancy and lactation. Dams easily established aggressive dominance over male cagemates soon after pairing, and their aggression was low thereafter for the duration of pregnancy and lactation. The aggression of dams with females, on the other hand, tended to fluctuate with highs during mid pregnancy and mid lactation and lows around birth. When dam aggression was low around birth, female cagemates frequently became aggressively dominant, and several dams lost their litters. The higher aggression of dams toward females than males is probably a reflection of greater intrasexual competition for environmental resources that includes pups.     

The influence of male and female best friends on adolescent sexual behavior

Using panel data from a junior high school system in an urban area of Florida, we examine whether adolescents' best same-sex and best opposite-sex friends' sexual intercourse behavior increases the likelihood that respondents who are virgins at round 1 will make the transition to intercourse between rounds of our study. We find no significant influence effects of friends of either sex for black males or females, or white males. In contrast, white females are influenced by the sexual behavior of both their best female friend and best male friend. A virgin white female whose best friends of both sexes were sexually experience at round 1 was almost certain to have sexual intercourse within the two years of our study.     

Maternal aggression toward infanticidal males of different social status in wild house mice (Mus musculus domesticus)

Maternal aggression was examined in wild female mice (Mus musculus domesticus) derived from animals trapped in Alberta, Canada. Lactating females were tested for their behavior toward intruder males during the time of postpartum estrus while housed in a two-cage apparatus containing a defensible nest area. Prior to being used as intruders, sexually naive males were screened for their behavior toward a newborn pup (83% exhibited infanticide). Only infanticidal males were then housed in pairs and allowed to establish a dominance hierarchy. Dominance status was further verified by a urine marking test. The dominant and subordinate infanticidal males were then placed into a lactating female's cage and observed for 1 hr. The test was terminated immediately when a male began to attack the pups. Lactating females attacked the males in both groups, but subordinate males received more intense attacks than dominant males. Dominant males elicited significantly more fear/defense behavior than subordinate intruders. All of the dominant males and only one submissive male attacked the pups. Females were thus successful in blocking infanticide only by infanticidal subordinate males. Since females do not persist in attacking males with high fighting ability, one function of maternal aggression could be to assess the fighting, and resource holding, potential of a future mate. © 1994 Wiley-Liss, Inc.     

Factors related to helping behavior in preschool-age children

The present two studies were conducted to assess the prosocial behaviors (comforting and helping) of preschool children as a function of the race and gender of the subjects and peer confederates. Results indicated that black, preschool-age males demonstrated prosocial behaviors more often than did white males and females. These findings were discussed in terms of the confounding between race of child and father absence; that is, a disproportionate number of black children were living in fatherless homes. It was suggested that single parents may turn to their opposite-sex child for both emotional and physical support and thus the child learns comforting and helping behaviors early in life. Support for this suggestion was derived from the finding that the number of household chores assigned to a child was positively related to helping behavior. The present results also showed that comforting and helping behaviors were negatively related, suggesting that prosocial acts are not a function of a general personality trait but are situationally specific. Finally, it was noted that race and gender of the peer confederate were not factors in determining the prosocial responses of the subjects.     

Perceptions of Self and of Ideal Mates: Similarities and Differences across the Sexes

For 19 mating-relevant traits, single males (N= 53) and single females (N= 86) rated (a) themselves relative to their same-sex peers, (b) their perceptions of the qualities desired by members of the opposite sex in an ideal partner, and (c) the qualities desired in their own ideal romantic partner. Several themes emerged from the data. First, males’ and females’ judgments of what members of the opposite-sex seek were generally accurate. Second, males and females both feel that they fall short of perceived opposite-sex expectations in a few areas. Third, both males and females desire an ideal partner better than themselves, but this is especially true for females. These findings are discussed in terms of evolutionary social psychological principles.     

Perceptions of self and of ideal mates: Similarities and differences across the sexes

For 19 mating-relevant traits, single males (N= 53) and single females (N= 86) rated (a) themselves relative to their same-sex peers, (b) their perceptions of the qualities desired by members of the opposite sex in an ideal partner, and (c) the qualities desired in their own ideal romantic partner. Several themes emerged from the data. First, males’ and females’ judgments of what members of the opposite-sex seek were generally accurate. Second, males and females both feel that they fall short of perceived opposite-sex expectations in a few areas. Third, both males and females desire an ideal partner better than themselves, but this is especially true for females. These findings are discussed in terms of evolutionary social psychological principles.     

Dexamethasone can prevent stress-related litter deficits in the golden hamster

This study was designed to examine the effects of social subordination during early pregnancy in the golden hamster (Mesocricetus auratus). Primiparous females were mated to proven breeders and stressed during early pregnancy. Females were housed singly throughout gestation except for Days 4, 5, and 6 when they were paired for 10-min intervals three times each day with another female matched for age, weight, and day of pregnancy. Within each of the pairs, one female was consistently dominant to the other. Controls were exposed to a novel area instead of a conspecific. At parturition, all pups were counted, sexed, and weighed. There were no significant differences between control and dominant females' litter sizes and sex ratios. Subordinate females produced significantly smaller litters than control or dominant dams and significantly lower sex ratios than control dams. Subordinates produced fewer males than control or dominant dams, but there were no differences in the number of females produced. The entire experiment was repeated exactly except that females received a small dosage of dexamethasone in their drinking water on Days 3-7 of pregnancy. In this second group, there were no significant reductions in mean litter size, sex ratio, or pup weights among litters born to subordinate dams. These results suggest that subordinate dams produce smaller litters via selective resorption of males in utero and that the typical adrenal response to stress mediates this response.