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.     

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.     

Subtyping versus bookkeeping in stereotype learning and change: connectionist simulations and empirical findings

A distributed connectionist network can account for both bookkeeping (M. Rothbart, 1981) and subtyping (M. B. Brewer, V. Dull, & L. Lui, 1981; S. E. Taylor, 1981) effects. The finding traditionally regarded as demonstrating subtyping is that exposure to moderate (compared with extreme) disconfirmers leads to subsequent ratings of the group that are less stereotypic. Despite learning that is incremental and analogous to bookkeeping, the simulations replicate this finding and suggest that the "subtyping" pattern of results will be drastically reduced if disconfirmers are encountered before the stereotype is well-established. This novel prediction holds with human participants and offers a tantalizing suggestion: Although moderate disconfirmers may produce more stereotype change. stereotype development might be discouraged by exposure to either extreme or moderate disconfirmers.     

Personal goals and psychological growth: testing an intervention to enhance goal attainment and personality integration

We hypothesized that semester goal attainment provides a route to short-term psychological growth. In an attempt to enhance this process, we randomly assigned participants to either a goal-training program or to a control condition. Although there were no main effects of program participation on later goal attainment, important interactions were found. Consistent with a "prepared to benefit" model, participants already high in goal-based measures of personality integration perceived the program as most useful and benefited the most from the program in terms of goal attainment. As a result, they became even more integrated and also increased in their levels of psychosocial well-being and vitality. Implications for theories of short-term growth and positive change are discussed, as is the unanswered question of how to help less-integrated persons grow.     

Smiling and relative status in news photographs

To test the hypothesis that lower social status is associated with more smiling, the authors used newspaper photographs and their associated news stories as the basis for scoring the smiling and relative social status of the 2 individuals in each photograph. Independent raters judged smiling and 5 dimensions of relative status for 496 individuals in 248 newspaper photographs. There was no relation between status and smiling, although status and smiling were both related to other variables such as gender, age, and story valence. These findings add to a growing body of evidence that there is no generalized relation between smiling and status.     

Differential age effects for case and hue mixing in visual word recognition

The authors compare older adults' lexical-decision data with younger adults' data reported in P. Allen, A. F. Smith, et al. (2002). On the basis of their work, it was proposed that consistent-case wordswould be processed by the faster holistic (magnodominated) stream, but that mixed-case words would be processed by the slower analytic (interblob-dominated or blob-dominated) steams. Hue mixing was predicted to have no effect on consistent-case performance, but mixed-hue/mixed-case words were predicted to be recognized faster than monochrome/mixed-case words. Younger adults showed the predicted results, but older adults did not. These results suggest that holistic central processes are maintained, but that older adults exhibited an analytic decrement     

The automatic evaluation of novel stimuli

From classic theory and research in psychology, we distill a broad theoretical statement that evaluative responding can be immediate, unintentional, implicit, stimulus based, and linked directly to approach and avoidance motives. This statement suggests that evaluative responses should be elicited by novel, nonrepresentational stimuli (e.g., abstract art, "foreign" words). We tested this hypothesis through combining the best features of relevant automatic–affect research paradigms. We first obtained explicit evaluative ratings of novel stimuli. From these, we selected normatively positive and negative stimuli to use as primes in a sequential priming paradigm. Two experiments using this paradigm demonstrated that briefly presented novel prime stimuli were evaluated automatically, as they facilitated responses to subsequently presented target stimuli of the same valence just as much as did pictures or names of real objects. A final experiment revealed that exposure to novel stimuli produces muscular predispositions to approach or avoid them.