Self-stimulation and mating behavior in the male rat

Abstract.— A presumed relationship between selfstimulation of the brain and sexual behavior was studied in two experiments. In the first experiment the male rat was allowed self-stimulation during a period of 5 minutes and thereafter transferred to a mating cage with a female. No effects of the self-stimulation were recorded in the mating behavior. In the second experiment the male was allowed one intromission and thereafter presented with a lever for self-stimulation, still having access to the female. The sexual responses were completely inhibited, and selfstimulation at normal rate resumed. It was concluded that there is no necessary link between self-stimulation of the brain and sexual behavior.     

Relationship between mousekilling and conspecific aggression in the male rat

In order to investigate the relationships between mousekilling and conspecific aggression, behavioral variables of killer and nonkiller rats were compared in a “resident-intruder” paradigm, in resident as well as in intruder animals. The occurrence of offensive items (offensive sideways, attack) was significantly higher in killer rats when they were residents; their corresponding opponents displayed more defensive behaviors. No significant difference in aggressive behaviors was noted when the comparison was done in the intruders. These results and those of previous studies suggest that there is a correlation between mousekilling and intraspecific offensive behaviors. Some similarities in the situations where both behaviors are elicited–eg, introduction of an unfamiliar intruder into a familiar environment–may contribute to the existence of such a correlation and the possibility of common mechanisms underlying both behaviors is discussed.     

Hormones and competitive aggression in women

This study used diaries of competitive interactions to explore the relationship between hormones and competitive aggression in women. Thirty women completed approximately 10 diary entries each. In each entry, the women described a recent competitive interaction they had engaged in and noted whether it was expressed aggressively or through other tactics. Each woman received a score for the fraction of her competitive interactions that were expressed using physical aggression, verbal aggression, nothing overt, and so on. Hormones (total testosterone, free testosterone, androstenedione, estradiol, and cortisol) were measured in serum early in the follicular phase. Results indicate that women with low levels of androstenedione and total testosterone were less likely to express their competitive feelings overtly, while women with high levels of androstenedione were more likely than other women to express their competitive feelings through verbal aggression. Estradiol was unrelated to competitive tactics, but women with high estradiol levels reported fewer competitive interactions over athletics than did other women. Aggr. Behav. 29:107–115, 2003. © 2003 Wiley‐Liss, Inc.     

Sex differences in instigative aggression

The instigative aggression paradigm, in which male and female subjects instructed a female confederate which shock to set for an opponent in a competitive reaction time task, was employed. It was observed that males instigated more aggression than females and that both passive and assertive noncooperation effectively reduced instigative aggression, the assertive form of noncooperation being only slightly less effective. Questionnaire data suggested that females found the passive noncooperator most desirable while males found her least so. Results were discussed in terms of violation of task role and sex role expectations.     

male self-control and sexual aggression

This study examines judgments of male self-control regarding sexual aggression in dating situations. A survey was conducted using vignettes that described situations where a hypothetical man attempts to have intercourse with his female date, she resists, and he considers various ways of overcoming her resistance. Survey respondents judged these vignettes. The goals of the study were to estimate the prevalence of beliefs about low male self-control, and to examine how contextual information affects these assessments. Contrary to expectations derived from the literature, the large majority of respondents attributed high levels of self-control to men across a wide range of scenarios. As expected, the man's alcohol intoxication reduced perceived control. Against expectations, consensual foreplay and prior sex did not affect ratings. Implications for social learning and rational choice theories of sexual aggression are discussed, with particular emphasis on Ajzen's (1988) theory of planned behavior.     

Fear and aggression in the rat

The effect of fear on two types of aggression in rats was investigated by adding a cat stimulus to a colony in which the dominant male was attacking an intruder (offensive aggression), or, to a tube test situation in which defensive biting was measured before and during tail shock. The cat completely abolished offense in the colony; when the cat was presented and removed before a strange rat was placed in the colony, attack on the intruder was also reduced. In contrast, defensive biting was unchanged or even slightly potentiated by the presence of the cat, demonstrating a separation of the effects of fear on offensive and defensive aggression.     

Sex in the City: The ambiguity of female mating strategies

Abstract

The purpose of this paper is to discuss the limitations of evolutionary explanations of female mating strategies, and to present an alternative theory that accounts for the ambiguity of mating strategies throughout a woman's life. While mating strategies are considered to be discrete entities, it is clear that women's decision making in everyday life is based on mutually fused, ambiguous courses of actions. The current perspective addresses the commonality of female mating experiences while highlighting the uniqueness of each woman's mating strategy and outlines a multi-level perspective on strategies of women's reproductive decision making.     

Predicting laboratory aggression against female and male targets: Implications for sexual aggression

This study assessed the ability of several variables to predict men's laboratory aggression against female and male victims. The predictors were chosen on the basis of their associations with sexual aggression against women in naturalistic settings. On the whole, these variables successfully predicted laboratory aggression against the female target but were not similarly related to aggression against the male. The data supported the view that specific factors uniquely contribute to aggression against women. It is suggested that, at least in part, such aggression needs to be examined within the larger context of sexist relations.     

Exploitative male mating strategies: Personality, mating orientation, and relationship status

Previous research suggests men are sexually attracted to women displaying cues to sexual exploitability. During human evolutionary history, men’s agreeableness, orientation towards casual sex, and relationship status may have been recurrently associated with greater net benefits of pursuing a sexually exploitative strategy. We hypothesized these three individual differences would predict men’s perceptions of women’s sexual exploitability. Seventy-two men viewed photographs of women and rated their sexual exploitability. Men’s agreeableness, sociosexual orientation, and current relationship status interacted to predict their perceptions of women’s sexual exploitability; among unmated men, the combination of low agreeableness and an orientation toward uncommitted sex was associated with higher perceptions of women’s sexual exploitability. This suggests mechanisms motivating sexually exploitative strategies may depend on an interaction between personality characteristics and situational variables.     

Physical/verbal aggression: Sex differences in style1

Two studies exploring the use of physical/verbal aggression are reported, the first using women and the second using men as subjects. Both studies allowed subjects to choose between and control the intensity of two response modes: verbal aggression (insults) and physical aggression (electric shock). Aggressive style was investigated over two levels of arousal, sex of experimenter, and sex of provocateur-victim. Results indicated that women aggressed discriminatively in the verbal mode as a function of their arousal, while men were capable of aggressing discriminatively in both the verbal and physical modes. Men who had been disagreed with and punished by a female victim-provocateur in the presence of a male experimenter or by a male victim in the presence of a female experimenter demonstrated high levels of physical aggression compared to the other groups.     

Effects of male testosterone and its interaction with cortisol on self- and observer-rated personality states in a competitive mating context

Increases in men’s testosterone (T) levels after intrasexual competitions and exposure to females facilitate competitive and courtship behaviours, suggesting T reactivity should affect relevant personality state changes. How exactly T reactivity, also under potential buffering effects of cortisol (C), relates to personality state changes is unclear. In a preregistered study, we aimed at inducing T increases in young men (N = 165) through dyadic intrasexual competitions while exposed to a female experimenter. We investigated self-reported and video-based observer-rated personality state changes, captured by the interpersonal circumplex and social impressions, in relation to hormonal levels. Results revealed increases in self-reported competitiveness and observer-rated self-assurance, relative to a control group, moderated by T reactivity and partly by T × C interactions, providing insights into hormone-personality response-links.     

Sex differences in genetic and environmental effects on aggression

The aim of the present study was to investigate the genetic and environmental factors influencing teacher and parental rated aggression in boys and girls, asking whether the magnitude of these effects is similar across rater and sex. The study is part of an ongoing nationwide twin‐family study of behavioral development and health habits carried out in Finland. The sample consisted of 1651 twin pairs (264 monozygotic male, 300 monozygotic female, 292 dizygotic male, 278 dizygotic female, and 517 dizygotic opposite‐sex twin pairs), representing subsets of five 11‐ to 12‐year‐old twin cohorts (b. 1983–1987). The data were collected using the teacher and parental rating forms of the Multidimensional Peer Nomination Inventory. Structural equation models of sex‐limitation assessed sex differences in genetic and environmental influences on aggression. The results suggested significant genetic, common environmental, and specific environmental effects on aggression in both boys and girls, but the best fitting model differed depending on the informant. For both ratings, boys showed lower levels of heritability and higher levels of common environment than girls. In addition, the teacher rating data also suggested the presence of either sex‐specific common environmental effects or sex‐specific genetic effects. Support is provided also for sibling contrast effects, either at the behavioral level or as a rater bias. Aggr. Behav. 29:55–68, 2003. © 2003 Wiley‐Liss, Inc.