Extracting thresholds from noisy psychophysical data.

Psychophysical studies with infants or with patients often are unable to use pilot data, training, or large numbers of trials. To evaluate threshold estimates under these conditions, computer simulations of experiments with small numbers of trials were performed by using psychometric functions based on a model of two types of noise: stimulus-related noise (affecting slope) and extraneous noise (affecting upper asymptote). Threshold estimates were biased and imprecise when extraneous noise was high, as were the estimates of extraneous noise. Strategies were developed for rejecting data sets as too noisy for unbiased and precise threshold estimation; these strategies were most successful when extraneous noise was low for most of the data sets. An analysis of 1,026 data sets from visual function tests of infants and toddlers showed that extraneous noise is often considerable, that experimental paradigms can be developed that minimize extraneous noise, and that data analysis that does not consider the effects of extraneous noise may underestimate test-retest reliability and overestimate interocular differences.     

Conditioned and unconditioned caloric compensation: Evidence for self-regulation of food intake in young children

The purpose of these two experiments was to determine (a) whether young children can be responsive to caloric density cues in regulating their food intake, (b) whether such cues can be associatively conditioned to organoleptic cues in foods, and (c) to obtain evidence regarding which of the many cues available are involved as conditioned stimuli. In Experiment 1 participants were eighteen 3- to 5-year-old children, who were seen for a series of pairs of conditioning trials, followed by extinction test trials. Each trial consisted of a two-part snack: approximately 100 ml of a pudding preload (chocolate or vanilla; high or low caloric density) followed after a delay by ad-lib consumption of snack foods (cookies and crackers). In extinction trials, flavors previously paired with high- or low-caloric density preloads during conditioning were presented in isocaloric intermediate density preloads. Results indicated that 14 of 18 children showed unconditioned caloric compensation on the first pair of conditioning trials; 16 of 18 children showed compensation following the second pair of trials, and 12 of these 16 subjects continued to show this consumption pattern during extinction. Consumption was significantly greater following the low calorie paired flavor than following the high calorie paired flavor during extinction. Experiment 2 (N = 10) replicated these findings, and uncorrelating preload and snack food flavors indicated that flavor cues in the preloads can serve as conditioned stimuli. Children showed both initial responsiveness to caloric density and evidence for associative conditioning of food cues to the physiological consequences of eating. These results provide initial evidence for a mechanism allowing the child to learn to anticipate the caloric consequences of familiar foods and regulate food intake accordingly.     

Ingroup Versus Outgroup Perceptions of the Characteristics of High-Risk Youth: Negative Stereotyping1

Adolescents tend to categorize themselves and their peers into discrete ingroups and outgroups. A comparison of ingroup versus outgroup perceptions of the characteristics of high-risk youth was investigated. Based on current stereotype research, we examined the perspective that outgroup members would hold a more extreme stereotype of high-risk youth compared to the perceptions of ingroup members. A total of 955 7th- and 10th-grade southern California adolescents completed a questionnaire regarding the characteristics of their own peer group and a high-risk group. Support was obtained for an extremity of judgement effect. Outgroup youth perceived that their high-risk peers engaged in fewer school and nonschool low-risk activities, more high-risk activities, and greater drug use than did ingroup members. Outgroup members also held perceptions of high-risk youth as less likely to hold a white-collar job than did the ingroup members. The perceptions that adolescents have of these groups may play major roles in their own social behavior. The implications of these results for future tobacco use prevention programs are considered.     

Peer-group association and adolescent tobacco use

Mosbach & Leventhal (1988) examined the relation of cigarette smoking to peer-group identification in rural Wisconsin adolescents. They found that among dirts (problem-prone youth), regulars (average youth), hot-shots (good social or academic performers), and jocks (athletes), youth most likely to smoke were dirts and hot-shots. We performed a replication with a Southern California cohort and also for use of smokeless tobacco. We hypothesized that jocks would be the main users of smokeless tobacco. We identified the same groups and an additional one, skaters (skateboarders or surfers). As Mosbach & Leventhal found, cigarettes were used most by dirts. Contrary to their results, but consistent with other research, we found that hot-shots were least likely to smoke. Contrary to our prediction, we found that skaters and dirts were more likely to use smokeless tobacco than were jocks. Our data show that both tobacco forms are used by problem-prone youth.     

Expectancy models of alcohol use

The primary goal of the present article is to compare expectancy models with competing attitude models of alcohol use. First, several methodological issues in expectancy research were addressed, to more adequately compare the theoretical models. Study 1 examined the effect of possible self-report biases on associations among expectancy constructs and alcohol use. In Studies 2 and 3, the basic distinction between general factors of positive and negative alcohol expectancies was investigated in both cross-sectional and prospective models. Alternative predictions that were based on competing expectancy and attitude theories were evaluated primarily in Study 3. Results from these studies supported the validity of the expectancy constructs and the proposed distinctions among expectancy and attitude constructs-in terms of strong discriminant validity, absence of self-report bias, and differential prediction of alcohol use. Furthermore, the findings favored certain expectancy models over alternative attitude models of alcohol use, reaffirming the usefulness of the expectancy framework.     

Perceptions of male and female success or failure in relation to spouse encouragement and sex-association of occupation

Male and female subjects read four paragraphs portraying successful (experiment 1) or unsuccessful (experiment 2) males or females in masculine or feminine occupations, with a supportive or nonsupportive spouse. The likelihoods of various conflicts, consequences, and causes of the success or failure were rated. Generally, ratings of more negative consequences were associated with lack of spouse support for a career pursuit. Spouse support influenced perceptions of female more than male success. The sex-association of the career proved to be an important determinant of perceptions of conflict, consequences, and attributions for the success or failure. Although male and female occupations had been equated for status, female jobs appeared to be generally devalued relative to male jobs.     

Cognitive motivation and drug use: a 9-year longitudinal study.

The predictive precedence of expectancy constructs, operationally defined as cognitive motivations, and drug use was investigated over a 9-year period from adolescence to adulthood. Alternative predictions from three different classes of theories of expectancy-behavior relations, including expectancy theory, a Skinnerian approach, and a reciprocal determinism perspective, were evaluated. The results are most consistent with the notion based in expectancy theory that cognitive motivations are nonspurious and possibly functionally autonomous influences on the use and abuse of drugs. More limited support is found for the view that drug use leads to cognitive motivations, as postulated in other theoretical perspectives. Other findings reveal the presence of expectancy generalization processes consistent with Rotter's (1954) expectancy theory, as well as the unique status of cognitive motivations for alcohol as an independent predictor of problem drug use.     

On the scope of alcohol expectancy research: remaining issues of measurement and meaning

An article by Leigh (1989d) examined certain substantive and measurement-related limitations of research on alcohol outcome expectancies. Leigh (1989d) criticized research in this field on both conceptual and methodological grounds and speculated on future theoretical directions for research in the field. In their response, Goldman, Brown, Christiansen, and Smith (1991) contended that Leigh's critique is faulty in important respects. However, some of their points are based on misinterpretations of Leigh's comments, and they appear to have insufficient appreciation of conditions necessary for comprehensive measurement validation and for meaningful application of theories of memory to alcohol expectancy research. Despite the limitations of expectancy research, exciting avenues exist for further work.