Similar and different: The differentiation of basic-level categories.

Categories in the middle level of a taxonomic hierarchy tend to be highly differentiated in that they have both high levels of within-category similarity and low levels of between-category similarity. Research on similarity reveals a distinction between pairs of categories that are seen as dissimilar because they have few commonalities and pairs that are seen as dissimilar because they have many psychologically relevant alignable differences. The authors suggest that the low between-category similarity proposed for neighboring basic-level categories is actually a matter of having many psychologically relevant differences. In contrast, the low between-category similarity of superordinates is a result of their having few commonalities. The authors evaluate this claim in 4 experiments using a variety of natural stimuli and converging measures. The data support the importance of alignable differences for distinguishing between pairs of basic-level categories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Children's use of frequency information for trait categorization and behavioral prediction.

Two experiments examined young children's use of behavioral frequency information to make behavioral predictions and global personality attributions. In Experiment 1, participants heard about an actor who behaved positively or negatively toward 1 or several recipients. Generally, children did not differentiate their judgments of the actor on the basis of the amount of information provided. In Experiment 2, the actor behaved positively or negatively toward a single recipient once or repeatedly. Participants were more likely to make appropriate predictions and attributions after exposure to multiple target behaviors and with increasing age. Overall, children's performance was influenced by age-related positivity and negativity biases. These findings indicate that frequency information is important for personality judgments but that its use is affected by contextual complexity and information-processing biases. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relative use of necessity and sufficiency information in causal judgments about natural categories.

Participants in 4 studies placed less emphasis on necessity information (instances when the event occurred but the target factor was absent) than sufficiency information (instances when the target factor was present but the event did not occur) when the target factor corresponded to a natural kind category (e.g., race or species) in comparison with an artificial category (e.g., preferences or facial features) or an artifactual category (e.g., product type). Results were not due to differences in familiarity, prior causal beliefs, or ease of imagining the class of instances, but instead derived from less willingness to search for alternative explanations when the target explanation was based on a natural kind category in comparison with artificial or artifactual categories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Children's use of mental state information in selecting persuasive arguments.

Whether and when children use information about others' mental states to invent or select persuasive strategies were examined. In Study 1, preschoolers, 3rd-graders, and 6th-graders (ns?=?11, 12, and 16, respectively; 17 girls) were told about story characters' persuading parents to buy pets or toys. Children were either given or not given information about story parents' beliefs and asked to invent or select appropriate arguments. Older children, but not preschoolers, used belief information to select arguments. Results were replicated in Study 2 (16 kindergartners, 16 3rd-graders; 19 girls). In Study 3, kindergartners and 1st-graders (N?=?16; 6 girls) reasoned well on false-belief tasks but not on persuasion tasks, suggesting that failure to consider mental states in persuasion was not due to lack of a belief concept. Findings suggest that mental state understanding may continue to develop after the preschool years; methodological qualifications are also considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Children's use of situational information to infer emotion: Understanding emotionally equivocal situations.

Children's recognition of individual differences in people's emotional reactions to situations was investigated. Children in kindergarten, first, second, and third grades heard scenarios in which a child experienced an emotionally equivocal or unequivocal event. Children were asked several questions to assess their ability to discriminate between the equivocal and unequivocal situations. Results indicated that school-age children are aware that almost everyone feels the same about unequivocal situations but that there are individual differences in reactions to equivocal situations. Yet these children often fail to consider that a particular individual might feel 1 of 2 different emotions in an equivocal situation. The ability to consider more than one emotional possibility for an individual increases with age. Two follow-up studies helped to clarify the meaning of these findings. Implications for children's social sensitivity are discussed. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Explaining basic categories: Feature predictability and information.

The category utility hypothesis holds that categories are useful because they can be used to predict the features of instances and that the categories that tend to survive and become preferred in a culture (basic-level categories) are those that best improve the category users' ability to perform this function. Starting from this hypothesis, a quantitative measure of the utility of a category is derived. Application to the special case of substitutive attributes is described. The measure is used successfully to predict the basic level in applications to data from hierarchies of natural categories and from hierarchies of artificial categories used in category-learning experiments. The relationship of the measure to previously proposed indicators of the basic level is discussed, as is its relation to certain concepts from information theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Children's use of triadic eye gaze information for "mind reading."

Five experiments examined children's use of eye gaze information for "mind-reading" purposes, specifically, for inferring another person's desire. When presented with static displays in the first 3 experiments, only by 4 years of age did children use another person's eye direction to infer desires, although younger children could identify the person's focus of attention. Further, 3-year-olds were capable of inferring desire from other nonverbal cues, such as pointing (Experiment 3). When eye gaze was presented dynamically with several other scaffolding cues (Experiment 4), 2- and 3-year-olds successfully used eye gaze for desire inference. Scaffolding cues were removed in Experiment 5, and 2- and 3-year-olds still performed above chance in using eye gaze. Results suggest that 2-year-olds are capable of using eye gaze alone to infer about another's desire. The authors propose that the acquisition of the ability to use attentional cues to infer another's mental state may involve both an association process and a differentiation process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When bad isn't all bad: Strategic use of sample information in generalization and stereotyping.

The influence of the reliability and valence of sample information on generalization to in-group and out-group target populations was investigated in 2 studies. In both studies the valence of the information was either favorable (i.e., a positive in-group sample and a negative out-group sample) or unfavorable. The reliability of sample information was manipulated in terms of sample variability (Study 1) and sample size (Study 2). In both studies the perceived central tendency of favorable sample information was directly generalized, but unfavorable and unreliable sample information was not. Moreover, generalizations based on unfavorable and unreliable samples were characterized by enhanced variability estimates for both in-group and out-group populations, thereby undermining unfavorable group differences. These results are discussed in terms of strategic use of sample information in the formation of social stereotypes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Disordered eating and substance use in an epidemiological sample: II. Associations within families.

This study investigated familial associations of disordered eating (DE) with substance use and substance use disorders (SU/SUDs) in a community-based sample of 620 adolescent girls, their 310 mothers, and 299 fathers. Female participants completed structured interviews of lifetime anorexia nervosa, bulimia nervosa, binge eating disorder, and SU/SUD; daughters also completed a self-report measure of current DE attitudes and behaviors. Fathers completed interviews assessing lifetime SUD. Evaluation of independent and combined associations of mothers' bulimic eating disturbance (ED) and parents' SUDs with daughters' DE/EDs and SU/SUDs revealed links between mothers' ED and daughters' DE but no relationship between EDs and SU/SUDs across generations. These results suggest that these problems are not cross-transmitted within families and suggest that the addiction model of eating disorders may be simplistic. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Substance use diagnosis within a community sample of adults: Distinction, comorbidity, and progression over time.

Practicing psychologists conceptualize, assess, and treat clients who use substances in different ways. Using longitudinal data from a multiethnic community sample of 470 adults, the authors examine patterns of abuse and dependence on alcohol, marijuana, and cocaine. Men were significantly more abusive, dependent, and polysubstance dependent on all drugs than women. A large percentage of drug abusers, and over 1/3 with drug dependence, remitted without formal treatment. However, early severe problems with cocaine increased later alcohol problems. Traditional disease progression and drug use acquisition models are not supported. Psychologists should incorporate the natural course of substance use into treatment and prevention efforts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Children's concurrent use of rehearsal and organizational strategies.

This study examined whether children could benefit from the simultaneous use of two mnemonic strategies. In Experiment 1, 3rd and 6th graders were taught to use the rehearsal and organizational strategies of same- or different-aged peers. At both ages, Ss who used developmentally advanced techniques recalled more than those who sorted and rehearsed like younger children; moreover, use of both efficient strategies together increased recall additively. In Experiment 2, 3rd graders rehearsed in any way they wished while learning taxonomically related or unrelated items. With each type of materials, 4 groups differed in whether the items were left visible, in whether Ss were asked to sort, and, if so, in whether they were instructed to sort to "help them remember" or on the basis of meaning. Those Ss instructed to sort showed higher recall and more active rehearsal, regardless of type of sort instructions or items. Thus, the use of one strategy may elicit effective use of another. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recalibration of phonetic categories by lipread speech versus lexical information.

Listeners hearing an ambiguous phoneme flexibly adjust their phonetic categories in accordance with information telling what the phoneme should be (i.e., recalibration). Here the authors compared recalibration induced by lipread versus lexical information. Listeners were exposed to an ambiguous phoneme halfway between /t/ and /p/ dubbed onto a face articulating /t/ or /p/ or embedded in a Dutch word ending in /t/ (e.g., groot [big]) or /p/ (knoop [button]). In a posttest, participants then categorized auditory tokens as /t/ or /p/. Lipread and lexical aftereffects were comparable in size (Experiment 1), dissipated about equally fast (Experiment 2), were enhanced by exposure to a contrast phoneme (Experiment 3), and were not affected by a 3-min silence interval (Experiment 4). Exposing participants to 1 instead of both phoneme categories did not make the phenomenon more robust (Experiment 5). Despite the difference in nature (bottom-up vs. top-down information), lipread and lexical information thus appear to serve a similar role in phonetic adjustments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estimation of the sample size in clinical and epidemiological investigations

Various kinds of lipophilic analogues of isonicotinic acid hydrazide (Isoniazid) were synthesized and in vitro explored in a search for antimycobacterial agents with extended activity spectrum against pathogens responsible for the AIDS-associated diseases. The primary in vitro screening showed that a) isonicotinoylhydrazones 1a, 1b, 1d, 1e are more active than the parent drug against non-tubercular mycobacteria (MIC ranging between 0.5 and 4 micrograms/ml), b) isonicotinohydrazides 6b and 6e display interesting antibacterial activity on some Gram + and Gram-strains, and c) trifluoromethyl-containing compounds 1a and 2c inhibit the growth of several human tumor cell lines at doses between 10(-5) and 10(-6) M. On the contrary, none of the tested analogues significantly counteracts the cytopathogenicity induced by HIV and HSV viruses.     

Waterfalls and geysers: the development of diversity awareness at Children's Hospital

The development of diversity awareness at Children's Hospital in Columbus, Ohio, has been a work in progress since the early 1980s. The interface of administration and individual initiatives ("waterfalls" and "geysers") has resulted in projects ranging from major international exchange programs to noontime Spanish language classes. This article recounts the journey from a parochial focus to a consciousness of multiculturalism in virtually all aspects of hospital interaction.     

Power and sample size calculations for studies involving linear regression

This article presents methods for sample size and power calculations for studies involving linear regression. These approaches are applicable to clinical trials designed to detect a regression slope of a given magnitude or to studies that test whether the slopes or intercepts of two independent regression lines differ by a given amount. The investigator may either specify the values of the independent (x) variable(s) of the regression line(s) or determine them observationally when the study is performed. In the latter case, the investigator must estimate the standard deviation(s) of the independent variable(s). This study gives examples using this method for both experimental and observational study designs. Cohen's method of power calculations for multiple linear regression models is also discussed and contrasted with the methods of this study. We have posted a computer program to perform these and other sample size calculations on the Internet (see http://www.mc.vanderbilt.edu/prevmed/psintro+ ++.htm). This program can determine the sample size needed to detect a specified alternative hypothesis with the required power, the power with which a specific alternative hypothesis can be detected with a given sample size, or the specific alternative hypotheses that can be detected with a given power and sample size. Context-specific help messages available on request make the use of this software largely self-explanatory.     

Factor analysis of the Children's Depression Inventory in a community sample.

The factor structure of the Children's Depression Inventory (CDI; M. Kovacs, 1992) was evaluated in a large community sample of 1,777 children and 924 adolescents. There were 5 first-order factors (Externalizing, Dysphoria, Self-Deprecation, School Problems, and Social Problems) for the child group; the adolescent group yielded the same 5 factors plus a 6th factor (Biological Dysregulation). Confirmatory factor analyses supported the stability and replicability of the obtained factor structures. Both samples yielded 2 higher order factors—Internalizing and Externalizing. The factors were compared with previous CDI factors identified for clinical (B. Weiss et al., 1991) and community (M. Kovacs, 1992) samples. Other notable findings included more boys reporting high scores (17 and above) on the CDI among the child sample, whereas, among adolescents more girls reported high scores (17 and above) on the total CDI as well as higher scores on the biological dysregulation factor. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multiple correlation: Exact power and sample size calculations.

This article discusses power and sample size calculations for observational studies in which the values of the independent variables cannot be fixed in advance but are themselves outcomes of the study. It reviews the mathematical framework applicable when a multivariate normal distribution can be assumed and describes a method for calculating exact power and sample sizes using a series expansion for the distribution of the multiple correlation coefficient. A table of exact sample sizes for level .05 tests is provided. Approximations to the exact power are discussed, most notably those of J. Cohen (1977). A rigorous justification of Cohen's approximations is given. Comparisons with exact answers show that the approximations are quite accurate in many situations of practical interest. More extensive tables and a computer program for exact calculations can be obtained from the authors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)