Genetic and environmental influences on pubertal development: longitudinal data from Finnish twins at ages 11 and 14

To study sources of individual differences in pubertal development, the authors fit a sex-limitation common factor model to data reported, at ages 11 and 14 years, by 1,891 twin pairs on items that comprise the Pubertal Development Scale (PDS; A. C. Petersen, L. Crockett, M. Richards, & A. Boxer, 1988). The model divides variation into a general pubertal factor and item-specific variation and, in addition, decomposes it into constituent sources. In both boys and girls, genetic influences made the largest contribution to variance common to PDS items. Genetic and nonshared environmental factors accounted for variation specific to PDS items in boys, whereas for girls, common environmental influences were added for growth spurt and menarcheal status. For both common and item-specific variation, genetic effects were partially sex specific. Subsidiary analyses found accelerated maturation in both boys and girls who at age 14 were reared in father-absent homes.     

A confirmatory analysis of the factor structure and cross-age invariance of the Wechsler Adult Intelligence Scale-Third Edition

In the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III; D. Wechsler, 1997), the manual reports several confirmatory factor analyses in support of the instrument's latent factor structure. In practice, examiners frequently compare an examinee's score from a current administration of the WAIS-III with the results from a previous test administration. Implicit in test-retest score comparisons is evidence that scores retain similar interpretive meaning across time. Establishing an instrument's factorial invariance provides the foundation for this practice. This study investigated the factorial invariance of the WAIS-III across the instrument's 13 age groups. The overall results from this study generally support both configural and factorial invariance of the WAIS-III when the 11 primary tests are administered.     

Temporal stability and consistency of aesthetic judgments of beauty of formal graphic patterns

Temporal stability and consistency of nonartists' aesthetic judgments of beauty of formal graphic patterns was assessed. Temporal stability decreased markedly over several months. When items were repeated in an aesthetic judgment task participants responded consistently over trials rather than performing genuine repeated aesthetic judgments of beauty.     

Discrimination of direction of movements in pigeons following previous experience of motion/static discrimination

Two experiments examined pigeons' discrimination of directional movement using pictorial images shown on computer monitors. Stimuli consisted of the movement of a bird against a stationary background or the movement of the background behind a stationary bird. In Experiment 1, pigeons were trained to discriminate either leftward or rightward motion of either the bird or the background from stationary frames drawn from the same movies. The background-discrimination group acquired the discrimination faster than the bird-discrimination group. In Experiment 2, transfer of the discrimination from the task of Experiment 1 to a discrimination between motion directions was examined. Most of the pigeons learned this discrimination rapidly, whereas in a pilot study in which direction discrimination was trained without previous static/movement discrimination, learning was poor. It appears that an experimental history of movement against stationary discrimination promoted the pigeons' learning of the directional motion discrimination.     

The matching law in and within groups of rats

In each of the two experiments, a group of five rats lived in a complex maze containing four small single-lever operant chambers. In two of these chambers, food was available on variable-interval schedules of reinforcement. In Experiment I, nine combinations of variable intervals were used, and the aggregate lever-pressing rates (by the five rats together) were studied. The log ratio of the rates in the two chambers was linearly related to the log ratio of the reinforcement rates in them; this is an instance of Herrnstein's matching law, as generalized by Baum. Summing over the two food chambers, food consumption decreased, and response output increased, as the time required to earn each pellet increased. In Experiment II, the behavior of individual rats was observed by time-sampling on selected days, while different variable-interval schedules were arranged in the two chambers where food was available. Individual lever-pressing rates for the rats were obtained, and their median bore the same “matching” relationship to the reinforcement rates as the group aggregate in Experiment I. There were differences between the rats in their distribution of time and responses between the two food chambers; these differences were correlated with differences in the proportions of reinforcements the rats obtained from each chamber.     

Biased lineups: sequential presentation reduces the problem.

Biased lineups have been shown to increase significantly false, but not correct, identification rates (Lindsay, Wallbridge, & Drennan, 1987; Lindsay & Wells, 1980; Malpass & Devine, 1981). Lindsay and Wells (1985) found that sequential lineup presentation reduced false identification rates, presumably by reducing reliance on relative judgment processes. Five staged-crime experiments were conducted to examine the effect of lineup biases and sequential presentation on eyewitness recognition accuracy. Sequential lineup presentation significantly reduced false identification rates from fair lineups as well as from lineups biased with regard to foil similarity, instructions, or witness attire, and from lineups biased in all of these ways. The results support recommendations that police present lineups sequentially.     

Identity Development in Adulthood: A Longitudinal Study

Identity status interviews involving five domains of life (religious beliefs, political ideology, occupational career, intimate relationships, and lifestyle) were conducted with 249 women and men at ages 27 and 36. The results on overall identity and domain-specific identities confirmed our general hypothesis as to the strengthening of the commitment process: (1) stability was higher in the identity statuses involving commitment (identity achievement and foreclosure) than in the statuses not involving commitment (identity diffusion and moratorium); (2) an increase in the salience of identity domains could be attributed to an increase in the commitment process; (3) transitions into identity statuses involving commitment were more frequent than transitions into statuses not involving commitment; indicating that both identity achievement and foreclosure might be end points of identity development. It was concluded that the results pointed to identity development in adulthood rather than to a random fluctuation in identity statuses over time.     

Elevated prolactin levels among adult male sex offenders

A sample of 528 successive admissions to the Phoenix Program, a voluntary inpatient treatment program for sex offenders, was studied in regards to serum prolactin levels. Serum prolactins were obtained as part of a battery of endocrine tests. A substantial number of patients had prolactin levels above the normal range, i.e., 21.0 microg/L. In this sample, fully 10.0% of the men showed elevated prolactin levels (the maximum being 41.0 microg/L), compared with an expected 2.5% according to laboratory norms. None of these individuals had clinical manifestations of prolactinoma. The significance of this increased rate of hyperprolactinemia in this sample of sexual offenders is unclear. There was a negative correlation with age and no correlation with other endocrine tests.     

A Permissive Theory of Territorial Rights

This article explores the justification of states' territorial rights. It starts by introducing three questions that all current theories of territorial rights attempt to answer: how to justify the right to settle, the right to exclude, and the right to settle and exclude with reference to a particular territory. It proposes a ‘permissive’ theory of territorial rights, arguing that the citizens of each state are entitled to the particular territory they collectively occupy, if and only if they are also politically committed to the establishment of a global political authority realizing just reciprocal relations. The article is developed by introducing some key features of the permissive theory and by explaining how such an account addresses the questions of settlement, exclusion and particularity in ways that significantly improve on existing rival accounts (most prominently: acquisition theories, legitimacy‐based theories and nationalist theories).