Major depression in the transition to adulthood: risks and impairments.

An ongoing longitudinal community study (N = 375) examined childhood risks and later adult impairments associated with 1-year Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.; American Psychiatric Association, 1987) diagnoses of major depression during the transition to adulthood. Risks from birth to age 9 were reported by mothers, participants, and teachers. Teacher-reported hostility at age 6 predicted later depression. At age 9, self-perceptions of anxiety/depression, unpopularity, familial rejection, and abuse were potent risks. For men, neonatal and childhood health problems predicted later depression. For women, risks included family constellation, parental death, and poor academic achievement at age 9. Men and women who were depressed at age 18, age 21, or both demonstrated extensive psychosocial impairments in early adulthood, including poor overall functioning, interpersonal and behavioral problems, low self-esteem, and suicidality.     

The Impact of Race,Racial Attitude,and Gender on Reactions to the Criminal Trial of O. J. Simpson1

Opinions about the criminal trial of O. J. Simpson, as well as general racial attitude, were assessed in different samples of African Americans and Whites in three studies: during jury selection (Study 1), after closing arguments (Study 2), and after the jury verdict was reached (Study 3). We assessed the effects of respondent race, gender, and general racial attitude on case opinion factors and guilt judgments at each point in time. Race was strongly related to case opinions and guilt judgments in all three studies. Racial attitude related significantly to guilt judgments only in Study 1 for Blacks and in Study 3 for Whites. Guilt judgments of Whites were more strongly predicted by the case opinion factors than were those of African Americans. General racial attitudes and opinions about the criminal justice system were more positive for Blacks in Studies 2 and 3, while they did not differ across studies for Whites. A hindsight bias was found for Whites but not for African Americans. Race had a more powerful impact than did gender. Across-study comparison suggested that very few respondents changed their views appreciably over the year-long trial.     

Logit models and logistic regressions for social networks: I. An introduction to Markov graphs andp

Spanning nearly sixty years of research, statistical network analysis has passed through (at least) two generations of researchers and models. Beginning in the late 1930's, the first generation of research dealt with the distribution of various network statistics, under a variety of null models. The second generation, beginning in the 1970's and continuing into the 1980's, concerned models, usually for probabilities of relational ties among very small subsets of actors, in which various simple substantive tendencies were parameterized. Much of this research, most of which utilized log linear models, first appeared in applied statistics publications.But recent developments in social network analysis promise to bring us into a third generation. The Markov random graphs of Frank and Strauss (1986) and especially the estimation strategy for these models developed by Strauss and Ikeda (1990; described in brief in Strauss, 1992), are very recent and promising contributions to this field. Here we describe a large class of models that can be used to investigate structure in social networks. These models include several generalizations of stochastic blockmodels, as well as models parameterizing global tendencies towards clustering and centralization, and individual differences in such tendencies. Approximate model fits are obtained using Strauss and Ikeda's (1990) estimation strategy.In this paper we describe and extend these models and demonstrate how they can be used to address a variety of substantive questions about structure in social networks.This research was supported by grants from the Australian Research Council and the National Science Foundation (#SBR93-10184). This paper was presented at the 1994 Annual Meeting of the Psychometric Society, Champaign, Illinois, June 1994. Special thanks go to Sarah Ardu for programming assistance, Laura Koehly and Garry Robins for help with this research, and to Shizuhiko Nishisato and three reviewers for their comments. INTERNETemail addresses:pattison@psych.unimelb.edu.au (PP);stanwass@uiuc.edu (SW). Affiliations: Department of Psychology, University of Melbourne (PP); Department of Psychology, Department of Statistics, and The Beckman Institute for Advanced Science and Technology, University of Illinois (SW).     

Successive matching-to-sample in the pigeon: Variations on a theme by Konorski

In 1959, Konorski proposed a successive matching-to-sample paradigm with which to study short-term memory in animals. Although the technique has been little used, it affords several distinct advantages over more commonly employed matching-to-sample procedures. Konorski’s paradigm involves the successive presentation of a pair of discriminative stimuli with a brief interstimulus interval between them. Reinforcement is scheduled to occur only when the second stimulus of a pair matches the first; otherwise, nonreinforcement follows. An investigation of the pigeon’s food-reinforced keypecking behavior is reported using a variant of Konorski’s technique. Pigeons rapidly learned to differentiate matching and nonmatching stimulus pairs when brief (5-sec) color stimuli were separated by a 1-sec interstimulus interval. No such differentiation arose when control subjects were trained with reinforcement equiprobable on matching and nonmatching trials. No support was found for the notion that correct performance under this successive-matching procedure was due to overt mediating behaviors.     

Differential autoshaping to common and distinctive elements of positive and negative discriminative stimuli

The learning by hungry pigeons of a discrimination between two successively presented compound visual stimuli was investigated using a two-key autoshaping procedure. Common and distinctive stimulus elements were simultaneously presented on separate keys and either followed by food delivery, S+, or not, S−. The subjects acquired both between-trial and within-trial discriminations. On S+ trials, pigeons pecked the distinctive stimulus more than the common stimulus; before responding ceased on S− trials, they pecked the common stimulus more than the distinctive one. Mastery of the within-display discrimination during S+ trials preceded mastery of the between-trials discrimination. These findings extend the Jenkins-Sainsbury analysis of discriminations based upon a single distinguishing feature to discriminations in which common and distinctive elements are associated with both the positive and negative discriminative stimuli. The similarity of these findings to other effects found in autoshaping—approach to signals that forecast reinforcement and withdrawal from signals that forecast nonreinforcement—is also discussed.     

Temporal factors influencing the pigeon's successive matching-to-sample performance: sample duration, intertrial interval, and retention interval

A successive matching-to-sample procedure that entails the sequential presentation of sample and test stimuli and the monitoring of response rates in a go/no-go discrimination of matching and nonmatching stimuli was studied as an alternative to the familiar delayed-matching paradigm of animal short-term memory. Three within-subject experiments studied the effects of sample duration (1 to 12 seconds), intertrial interval (5 to 50 seconds), and retention interval (1 to 50 seconds) on the pigeon's successive-matching performance. The results revealed that retention was (a) an increasing function of sample duration and intertrial interval, and (b) a decreasing function of retention interval. These results were in accord with those of more traditional short-term memory paradigms, and reveal the suitability of the successive-matching procedure for studying memory processes.     

The relationship between motor and secretory behaviors in classical appetitive conditioning

Three hungry dogs received pairings of food with an accessible, illuminated panel. This resulted in the dogs’ approaching the lighted panel and salivating. Despite the similarity of these conditioning procedures to those used in a large body of research primarily with avians, however, the dogs did not physically contact the lighted stimulus panel. These results bear on several issues concerning the form and direction of classically conditioned behaviors.