Elevation and reduction of plasma tryptophan and their effects on aggression and perceptual sensitivity in normal males

Data from experimental animals suggest that 5-hydroxytryptamine (5HT) may have an inhibitory effect on aggression, while clinical studies have found a correlation between pathological aggression and low brain 5HT. To investigate this relationship further we used amino acid mixtures designed to raise or lower the levels of the 5HT precursor, tryptophan. Normal male subjects were given tryptophan-depleted, balanced, or tryptophan-supplemented ammo acid mixtures and tested for aggression 5 hours later. The balanced amino acid mixture served as a control for the tryptophan depletion and supplementation. Testing for aggression was done using the Buss paradigm in which subjects deliver electric shocks to a (nonexistent) partner in response to stimulus tones. Duration and intensity of shock delivered were the measures of aggression, while responsivity to the stimulus tones was the measure of perceptual sensitivity. Neither tryptophan supplementation nor tryptophan depletion had any effect on these measures of aggression or perceptual sensitivity. We conclude that raising or lowering the synthesis of brain 5HT through alterations in tryptophan availability does not influence aggression in normal males as measured by the Buss task.     

A note on E. B. Titchener and G. M. Whipple

In 1898, one of E. B. Titchener's graduate students, Stella E. Sharp, conducted an experiment on Alfred Binet and Victor Henri's theory and belief that mental abilities should be tested by means of complex mental processes. Her subjects were seven advanced students in psychology. She concluded that the findings were incommensurate with the effort required. That closed the subject as an area of research and instruction in the Cornell Department of Psychology until 1941, when the subject of test theory and uses was included in that department's course offerings. This continued until 1963. Currently, the subject is once again being actively pursued in the Department of Education.     

The relationship between STD locus of control and STD acquisition among adolescent girls

This longitudinal study examined adolescent girls' perception of control over sexually transmitted disease (STD) acquisition. Participants were asked questions regarding their perception of their STD locus of control (internal control; control by parents, partners, peers, and health care providers; and chance) at two waves of data collection. Of the 116 participants (mean age = 17 years), 82% were African-American and 18% were Caucasian. Responses to the measure of locus of control were significantly correlated across a 6-month interval. The responses regarding internal control, control by partner, and chance were not related to the acquisition of an STD in the next 6 months. Further, they were not influenced by an STD in the preceding 6 months. These results indicate that responses to a locus of control measure were stable over a 6-month period, and internal, partner, and chance locus of control perceptions seem to be neither determined by STD experience nor directly related to future STD acquisition. However, understanding an individual's locus of control may be helpful in providing appropriate counseling. Future research could examine how adolescent girls form their perceptions of control over STD acquisition.     

Marital interaction of agoraphobic women: a controlled,behavioral observation study

Married couples with a female agoraphobic spouse (n = 22) were compared with demographically similar community control couples (n = 21) on self-report and observational measures of marital interaction. Consistent with hypotheses, husbands of agoraphobic women were more critical of their wives than were control husbands, and clinical couples were less likely to engage in positive problem solution than control couples. Contrary to hypothesis, clinical husbands were not less supportive than control husbands. Where general measures of marital distress were concerned, clinical couples, relative to control couples, evinced more distress by self-report, by their higher rate of negative nonverbal behavior, and by their longer sequences of negative exchanges.     

Crying threshold and intensity in major depressive disorder

Clinical lore suggests that depression is associated with frequent and intense crying. To test these postulations empirically, a standardized cry-evoking stimulus was presented to depressed and nondepressed participants, and their likelihood of crying and the magnitude of crying-related changes in their emotion experience, behavior, and autonomic physiology were compared. Unexpectedly, crying was no more likely in depressed than in nondepressed participants. Within the nondepressed group, participants who cried exhibited increases in the report and display of sadness and had greater cardiac and electrodermal activation than did participants who did not cry. There was less evidence of this crying-related emotional activation within the depressed group. The lack of emotional activation among clinically depressed participants who cried provides a tantalizing clue concerning how emotions are dysregulated in this disorder.     

Racial bias in decisions made by mock jurors evaluating a case of sexual harassment

White (N = 161) and Black (N = 152) college students served as mock jurors in a simulated civil case in which a female plaintiff accused a male defendant of sexual harassment. The authors experimentally manipulated the race (Black or White) of the litigants and asked the mock jurors to decide whether the defendant was guilty; to rate the certainty of their belief in the defendant's guilt; and, when they judged the defendant guilty, to recommend an award to the plaintiff. Mock jurors of both races tended to favor litigants of their own race and their own gender. Racial bias was highest among White male jurors and lowest among White female jurors.     

The self-importance of moral identity

Recent theorizing in moral psychology extends rationalist models by calling attention to social and cultural influences (J. Haidt, 2001). Six studies using adolescents, university students, and adults measured the associations among the self-importance of moral identity, moral cognitions, and behavior. The psychometric properties of the measure were assessed through an examination of the underlying factor structure (Study 1) and convergent, nomological, and discriminant validity analyses (Studies 2 and 3). The predictive validity of the instrument was assessed by examinations of the relationships among the self-importance of moral identity, various psychological outcomes, and behavior (Studies 4, 5, and 6). The results are discussed in terms of models of moral behavior, social identity measurement, and the need to consider moral self-conceptions in explaining moral conduct.