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.     

Energetic and motor responses to increasing force requirements

The effects of increasing work (force) requirements on energy expenditure and response topography were examined in 7 rats pressing a beam to earn food. For the 1st 16 days, the force requirement was 5.52 x 10(-2) N (5.625 g). This increased by 4.91 x 10(-2) N (5 g) every 7th session until Ss had experienced 10 upward shifts. Following the 54.57 x 10(-2) N (55.625 g) condition, the original criterion was reinstated. During the augmented phase. Ss maintained stable reinforcement rates across conditions by increasing the peak force of beam pressing. These higher forces, occurring within 20 reinforcements of changing the force criterion, were produced primarily by increases in the rate of change of force (delta F/delta T). Also, while the rate of work performed on the beam increased, the overall energy expenditure fell. In contrast to these rapid adjustments, reinstating the original 5.52 x 10(-2) N (5.625 g) criterion resulted in only gradual alterations in motor performance.     

Sequencing of behaviors in Aplysia fasciata: integration of feeding, reproduction, and locomotion.

To begin studying the neural basis of higher-order decision-making in Aplysia fasciata, we examined individual bouts of behavior in various conditions of access to food and/or mates. We then determined rules governing transitions between bouts. The data indicate that a single intermediate condition, moving in place, may be centrally related to transitions between behaviors. In all conditions, over 85% of all transitions between behaviors were via moving in place. Moving in place tended to precede and follow other categories of activity (crawling, swimming, immobile), and feeding. Also, moving in place apparently represents a fixed proportion of all bouts of behavior. In each condition, moving in place represented approximately 40% of all bouts, while the number of bouts of other behaviors varied markedly. After a bout of moving in place there was a strong tendency for the animal to return to the behavior performed before moving in place. Additional preferred sequences of behavior were also seen. Courtship tended to precede mating, and crawling preceded swimming.     

Septal lesions lower responding under fixed-ratio schedules of reinforcement.

Albino Sprague-Dawley rats with complete septal lesions and rats with control operations were studied under fixed-ratio (FR) schedules of reinforcement. Both groups were trained for 10 sessions each under FR 10, 20, 40, 60, 80, and 100. In contrast to findings from progressive FR studies and some simple FR studies, septal lesions resulted in lower overall and local response rates along with longer postreinforcement pauses. These effects were especially evident during the FR 100 schedule of reinforcement. A comparison of reinforcement rate as a function of FR size within the context of behavioral economics (i.e., a demand function) indicated that septal lesions did not alter the reward value of food. These findings suggest that responding on FR schedules of reinforcement can be altered by the various procedures used to train rats to reach the terminal value of a reinforcement schedule.     

Sexual experience effects are blocked both by the protein-synthesis inhibitor, cycloheximide, and by the noncompetitive NMDA antagonist, MK-801.

Three studies were done to determine the effects of a brief 2-h sexual experience on the maintenance of sexual behavior in male rats; the effects on the experience-based maintenance of sexual behavior of gonadal hormones (study 1), a protein-synthesis inhibitor (study 2), and an N-methyl-D-aspartate receptor blocker (study 3) were determined. Naive male rats were provided with a 2-h sexual experience with sexually receptive hormonally "primed" females or they received no experience. In the first study animals under each of these conditions then underwent castration or sham surgery. In the second study animals under each of the experience conditions received either cycloheximide (CYX) or saline (SAL; 1.5 or 3.0 mg/kg CYX or SAL sc, 10 min after the experience). In study 3 experienced and inexperienced animals received either 0.07 or 0.10 mg/kg MK-801 ip (15 min before the experience). In all studies animals were tested for sexual behavior 3, 6, and 9 days after surgery or injection. These studies showed that the most consistent effect of a 2-h sexual experience was to facilitate the initiation of mounting, especially on the first test; they show, further, that most experience effects were reduced or eliminated if animals were castrated between experience and test, if they received a drug (CYX) at the time of the experience that blocks the synthesis of proteins, or if they received an NMDA receptor antagonist prior to the experience.     

Effects of conspecifics on feeding in Aplysia fasciata

The presence of other Aplysia in the environment increases the time spent feeding. This finding is consistent with the hypothesis that a common arousal mechanism modulates feeding and reproductive behaviors. The arousal level is presumably increased by pheromones released by additional animals.     

Gender differences in tobacco use

Gender differences in overall tobacco use clearly exist. In general, men are more likely to use tobacco products than are women. However, this simple generalization, ignoring type of tobacco products, time, and culture, masks many more interesting gender differences in tobacco use. There are pronounced gender differences in tobacco use of specific tobacco products within some cultures but not others. Yet these differences have changed across time, including narrowing and widening of this gender gap, depending on culture and tobacco product. This article addresses these issues and presents possible psychosocial, biological, and psychobiological explanations for these phenomena. In addition, the implications of these differences and ways to learn more about these important differences are discussed.     

The job climate for women in traditionally male blue-collar occupations

Rapid growth has been observed in recent years in the number of women entering traditionally male blue-collar occupations, yet researchers have paid little attention to this pioneering group. The present study undertook a comparison of the job conditions of two groups of nontraditional women workers, tradeswomen (N=71), and transit workers (N=151); a third group, school secretaries (N=389), was studied as a comparison group of traditionally female workers. Results from a 16-page mail questionnaire revealed that women in traditionally male occupations encountered significantly more adverse working conditions than did their traditional counterparts, and, in addition, reported significantly less satisfaction and more stress at work. Tradeswomen were the most likely to experience sexual harassment and sex discrimination, and black tradeswomen to experience race discrimination. The degree of job satisfaction expressed by the secretaries was unexpected, since most evidence suggests that clerical workers lack autonomy, and encounter boredom and routinization on the job. These findings are discussed in terms of gender segregation and the need to focus future research efforts on specific occupational groups in order to make appropriate policy recommendations as well as to provide help for women in these jobs.This research was supported by grants from the National Institute for Occupational Safety and Health (Grant No. 1 RO1 OH02162-01A1) and the College of Health and Human Development, The Pennsylvania State University. The authors wish to acknowledge the invaluable contributions of Patty Lambert, Ming Qi Wang, Mary Harmon, Joseph Vasey, Gina Jay, Darrell Harvey, and Haleh Rastegary.     

Sex of child preferences among college students

In both 1985 and 1988, college student preferences for the sex of an only child were examined using social surveys. For both years, it was found that male students strongly prefer a male child, but that female students moderately prefer a female child. Gender of respondent accounted for most of the sex preference difference. The sex role attitude of agreement with having the wife retain her own name was the only other variable significantly related to sex preference. It is argued that differing male-female role expectations for women as wives and mothers partly explained the gender differences in sex preference for a child.     

THE IMPACT OF ROLE STRESSORS AND PERSONAL RESOURCES ON THE STRESS EXPERIENCE OF PROFESSIONAL WOMEN

This study explored the contributions of role stressors and personal resources in predicting strain symptoms experienced by 117 professional women employed full-time in academia. Results of multiple regression analyses revealed that, while role stressors alone accounted for only a moderate amount of the variance in reported strain symptoms, 51 % of the variance was explained when both stressors and personal resources were combined. Womend, who experienced higher levels of personal control and social support as well as a greater number of roles occupied reported lower levels of strain symptoms. These results support the use of a transactional model of stress in future multiple role research.