Aggressive behavior inhibition by serotonin and quipazine injected into the amygdala in the rat

The effects on aggressive behavior, open-field activity, and pain threshold of bilateral microinjections of serotonin (20 micrograms) and quipazine (20 micrograms), the direct serotonergic receptor agonist, into the cortico-medial amygdala were investigated in Wistar rats. Both drugs significantly prolonged the attack latency in isolated killer rats (predatory aggression model), and suppressed the incidence of aggressive postures/attacks in shock-induced fighting test (affective aggression). The only difference in the open-field behavior was the lower number of central square entries in drug-treated compared to saline-injected rats. None of the substances produced any significant change in jump threshold. It is concluded that stimulation of serotonin receptors within the amygdala produces inhibition of affective and muricidal behavior in isolated rats. The effect does not seem to be dependent on changes in general activity and pain sensitivity.     

A paradoxical prediction from locus of control

Individual differences in attribution have been little researched. Beliefs about locus of control have been taken to be stable and important differences between people. They may provide some of the background assumptions on which people base their explanations of actions, especially insofar as these explanations imply that the cause of an action was within the agent or his environment, and that the action was or was not under the agent's control. Respondents were therefore asked to fill in Rotter and Levenson locus of control questionnaires and to provide explanations or ask questions about several actions. It was hypothesized that internals would be inclined to go for explanations which were personal and implied high control, while externals would not. However, what emerged was the paradoxical finding that internals provided explanations which implied that the causes of the actions lay outside the agent, while externals provided ones which implied that the causes lay within. This result is discussed in terms of the difference between actions and outcomes, and the possibility that an important difference between people may be in the rigidity and simplicity of their beliefs about causality.     

Seeking urgent pediatric treatment: factors contributing to frequency, delay, and appropriateness

The present study explored the factors that contribute to mothers' decisions to seek urgent medical attention for their children when symptoms are not of a traumatic nature. One hundred mothers seeking treatment for their children at a prepaid clinic completed a questionnaire eliciting their expectations regarding the course of their children's problems, seriousness of the problems, perceived responsibility for the symptoms, and extent to which a variety of factors contributed to their decisions to seek treatment. Demographic data and information about each child's symptoms and medical history were also obtained. Four major "reasons for seeking treatment" factors were identified: family history of the presenting complaint, worry regarding the symptoms, situational variables, and the extent of the child's illness behavior. The appropriateness of the visit, delay in seeking treatment, and frequency of mothers' use of the pediatric clinic were predicted by the nature of the presenting symptoms (particularly the presence of fever), the ages of the mother and child, and two of the reasons for seeking treatment factors (i.e., family history and child's illness behavior). The present study suggests that mothers pay more attention to presenting symptoms and to the children's behavior than to psychosocial stressors in deciding to seek urgent care.     

Selective cardiovascular effects of stress and cigarette smoking in young women

In an earlier study, we found that men who smoked a cigarette and then engaged in a mildly stressful activity (video game) evidenced pronounced increases in heart rate and blood pressure, which were approximately equal to the sum of the effects produced by either smoking alone or stress alone. In the present study, a 2 (smoke vs. sham smoke) X 2 (stress vs. no stress) factorial design was used to evaluate the impact of stress and smoking on the cardiovascular responses of young women. The results revealed that the combination of stress and cigarette smoking produced blood pressure and heart rate responses that were larger than the additive effects of smoking and stress taken separately.     

Co-occurrent use of cigarettes, alcohol, and coffee in healthy, community-living men and women

Previous studies have examined intra-individual aggregation in the use of cigarettes, alcohol, and coffee by examining the co-occurrent use of any pair of these three substances. A recent literature review failed to find a single investigation that studied use of all three in the same sample. In the present study, co-occurrent use of all three of these substances was examined in crossvalidated subsamples of 226 male and 245 female healthy, community-living, middle-class Americans. A log-linear analysis was used to compare the proportion of smokers, ex-smokers, and nonsmokers categorized as users of more or less amounts of coffee and alcohol. Although most of the intercorrelations were not strong, the results indicate that for both sexes, smokers and ex-smokers were more likely than nonsmokers to drink greater amounts of alcohol and coffee. Furthermore, for smokers, ex-smokers, and nonsmokers, a majority of individuals who reported drinking more alcohol also reported drinking more coffee. Interestingly, the coffee and alcohol consumption levels of ex-smokers resembled those of smokers more than those of nonsmokers. Also, ex-smokers reported drinking more wine and decaffeinated coffee than either smokers or nonsmokers. Finally, the number of cigarettes smoked per day (daily quantity) was positively related to total alcohol and coffee consumption in men, but not in women. Further studies are recommended to examine the role of individual differences in the development, maintenance, and modification of these three appetitive habits and their co-occurrence.     

The inequivalence of self-reports of Type A behavior: Differential relationships of the Jenkins Activity Survey and the Framingham cale with affect,stress, and control

The Jenkins Activity Survey (JAS) and the Framingham Type A Scale (FTAS) have been found to have different psychological correlates. The JAS is typically unrelated to anxiety, while the FTAS is consistently correlated with trait anxiety. The present study of 200 male and female college students clarifies further the psychological heterogeneity of these measures. Enhanced motivation to control the environment has been suggested as an underlying psychological component of Type A behavior (Glass, 1977). Dysphoric emotions and the perception of more environmental stresses, on the other hand, are typical of neuroticism or negative affectivity (Watson & Clark, 1984). Although the results indicate that the JAS and FTAS are highly correlated, the JAS is more closely related to control motivation than is the FTAS. Further, compared to the JAS, the FTAS is more closely correlated with dysphoric emotions and perceived daily stresses. Thus, the results indicate that the JAS is closely correlated with core psychological components of the Type A pattern, while the FTAS has a relatively unique association with general emotional distress. Such differences may account for the fact that these measures are related to different disease end points.     

Intelligence and fertility in the United States: 1912-1982

Results are presented for the 1st analysis of the relationship between IQ and completed fertility using a large, representative sample of the US population. Correlations are predominantly negative for cohorts born between 1894 and 1964 but are significantly more positive for cohorts whose fertility was concentrated in the baby boom years. Previous studies reporting slightly positive correlations appear to have been biased in their restriction of samples to atypical cohorts. The National Opinion Research Center (NORC), a nonprofit research organization affiliated with the University of Chicago, conducted the General Social Survey (GSS) in the US each year from 1972 to 1982, except for 1979. A combination of block quota and full probability sampling was employed. Hour-long interviews were completed with 12,120 respondents who were English-speaking, noninstitutionalized adults (18 years or older) living within the continental US. Such questions as age, place of birth, income and occupation, were asked in each interview. Other questions about attitudes on various social, political, and moral issues were rotated in different years. The unique opportunity this data set affords is an overview of the relationship between intelligence and fertility for a nationally representative sample of Americans whose major reproductive years fell between 1912 and 1982. Data were consolidated from the 4 surveys in which the vocabulary test was given (1974, 1976, 1978, and 1982). Respondents were divided into 15 birth cohorts of 5-year intervals ranging from before 1894 to 1964. Correlations between vocabulary scores and number of siblings are markedly negative across all 15 cohorts. Vocabulary sibling correlations are more negative in every cohort than vocabulary offspring correlations. Previous reports of a neutral or slightly eugenic relationship appear to be due to the nature of the samples used, in part because the cohorts chosen were atypical, and in part because they did not include nonwhites. Childless respondents averaged slightly higher scores than did those with 1 or more children, indicating that the automatic exclusion of the childless from sibling-IQ studies has not spuriously inflated negative correlations.     

Ventral scent marking in Meriones unguiculatus may contribute to thermoregulation

Three experiments were conducted with adult male Meriones unguiculatus in an attempt to demonstrate that ventral scent marking can act to transfer body heat to the object marked. Experiment 1 showed that surgical removal of the ventral gland pad reduced the amount of heat transferred by 50%, even though intact and glandless animals did not differ in the average frequency of scent marking. Experiment 2 demonstrated that the difference in heat transfer due to the presence or absence of the scent pad was not due to differential pressure applied to the substrate during marking. Experiment 3 showed that the pattern of ventral hair spread that occurs as an animal moves over an object is different between intact and glandless animals but that this difference does not account for the difference in heat transfer. It is suggested that heat transfer to the environment with ventral scent marking may increase thermoregulatory competence and also may function to volatilize sebum used in chemocommunication.     

Chimpanzee (Pan troglodytes) spatial problem solving with the use of mirrors and televised equivalents of mirrors

Two adult male chimpanzees reached through a hole in the wall of their home cage and, by tracking the images of their hands and of an otherwise hidden target object in a mirror or closed-circuit television picture, moved their hands in whichever direction was necessary to make contact with the target object. They discriminated between live video images and tapes and performed effectively when the target objects were presented in novel locations and when the video picture was presented at random in different orientations. There was thus no consistent relation between the location of images on the monitor and the location of their real-world counterparts. Comparable performances in monkeys and nonprimates seem unlikely.