The heritability of attitudes: A study of twins.

The genetic basis of individual differences in attitudes was examined in a survey of 195 pairs of monozygotic twins and 141 pairs of same-sex dizygotic twins. A principal components analysis of the 30 attitude items in the survey identified 9 attitude factors, of which 6 yielded significant heritability coefficients. Nonshared environmental factors accounted for the most variance in the attitude factors. Possible mediators of attitude heritability were also assessed, including personality traits, physical characteristics, and academic achievement. Analyses showed that several of these possible mediators correlated at a genetic level with the heritable attitude factors, suggesting that the heritability of the mediator variables might account for part of the heritable components of some attitudes. There was also some evidence that highly heritable attitudes were psychologically "stronger" than less heritable attitudes. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The development of verbal memory in childhood and adolescence: Findings from the Munich Longitudinal Study.

The authors assessed developmental changes in verbal memory from the beginning of elementary school to late adolescence on the basis of data from the Munich Longitudinal Study. Major issues concern the stability of individual differences in strategy use as well as interrelationships among different components of verbal memory and the impact of educational context on verbal memory development. Long-term stability of strategic memory was low to moderate in late childhood and adolescence. Interrelations among the verbal memory components were also moderate and did not change much over time. Unexpectedly, no impact of educational context was found. Overall, individual differences in verbal memory performance develop very early in life and are relatively unaffected by differences in educational experiences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Infants' early ability to segment the conversational speech signal predicts later language development: A retrospective analysis.

Two studies examined relationships between infants' early speech processing performance and later language and cognitive outcomes. Study 1 found that performance on speech segmentation tasks before 12 months of age related to expressive vocabulary at 24 months. However, performance on other tasks was not related to 2-year vocabulary. Study 2 assessed linguistic and cognitive skills at 4-6 years of age for children who had participated in segmentation studies as infants. Children who had been able to segment words from fluent speech scored higher on language measures, but not general IQ, as preschoolers. Results suggest that speech segmentation ability is an important prerequisite for successful language development, and they offer potential for developing measures to detect language impairment at an earlier age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Longitudinal analysis of the genetic and environmental influences on components of cognitive delay in preschoolers.

The etiology of verbal and performance delays were investigated in a large population sample of twins at 2 and 3 years (N?=?2,449 pairs). These data replicate and extend earlier analyses at 2 years (T. C. Eley et al., 1999). Several ways of defining delay were compared, selecting from the lowest 5% of the sample on both verbal (V) and performance (P) measures. V delay with or without P delay was highly heritable (.93 and .62, respectively), whereas P delay without V delay was less heritable (.29), with substantial shared environment influence (.48). Longitudinal genetic analyses indicated substantial heritability of V delay from 2 to 3 years, especially in combination with P delay (.48 and .81, respectively). Similarly, genetic influence on continuity of P delay without V delay was much lower (.22). These results suggest that it is useful to consider the strong genetic contribution to verbal delay regardless of nonverbal impairment in preschoolers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A profile of neuropsychological deficits in alcoholic women.

Neuropsychological deficits, most notable in executive, visuospatial, and functions of gait and balance, are detectable in alcoholic men even after a month of sobriety. Less well established are the severity and profile of persisting deficits in alcoholic women. The authors used an extensive test battery to examine cognitive and motor functions in 43 alcoholic women who were sober, on average, for 3.6 months. Functions most severely affected in alcoholic women involved visuospatial and verbal and nonverbal working memory processes as well as gait and balance. Areas of relative sparing were executive functions, declarative memory, and upper-limb strength and speed. The authors found that lifetime alcohol consumption was related to impairment severity on Block Design (Wechsler Adult Intelligence Scale--Revised, D. Wechsler, 1981) and verbal and nonverbal working memory, suggesting a dose effect of alcohol abuse. The alcohol-related deficits in working memory, visuospatial, and balance implicate disruption of prefrontal, superior parietal, and cerebellar brain systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Covariance structure of neuroticism and agreeableness: A twin and molecular genetic analysis of the role of the serotonin transporter gene.

The Revised NEO Personality Inventory domains of Neuroticism and Agreeableness are considered factorially distinct despite several intercorrelations between these domains. The genetic correlation, an index of the degree to which these intercorrelations are caused by genetic influences, was estimated using data from 913 monozygotic and 562 dizygotic volunteer twin pairs from Canada, Germany, and Japan. The serotonin transporter gene, 5-HTTLPR, was assayed in a sample of 388 nontwin sibling pairs from the US to determine the contribution of the serotonin transporter locus to the covariation between the Neuroticism and Agreeableness scales. In all four samples, genetic influences contributed to the covariance of Neuroticism and Agreeableness, with the serotonin transporter gene accounting for 10% of the relationship between these domains. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The structure of working memory abilities across the adult life span.

The present study addresses three questions regarding age differences in working memory: (1) whether performance on complex span tasks decreases as a function of age at a faster rate than performance on simple span tasks; (2) whether spatial working memory decreases at a faster rate than verbal working memory; and (3) whether the structure of working memory abilities is different for different age groups. Adults, ages 20–89 (n = 388), performed three simple and three complex verbal span tasks and three simple and three complex spatial memory tasks. Performance on the spatial tasks decreased at faster rates as a function of age than performance on the verbal tasks, but within each domain, performance on complex and simple span tasks decreased at the same rates. Confirmatory factor analyses revealed that domain-differentiated models yielded better fits than models involving domain-general constructs, providing further evidence of the need to distinguish verbal and spatial working memory abilities. Regardless of which domain-differentiated model was examined, and despite the faster rates of decrease in the spatial domain, age group comparisons revealed that the factor structure of working memory abilities was highly similar in younger and older adults and showed no evidence of age-related dedifferentiation. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The downside of being talented.

Comments on D. Lubinski and C. P. Benbow's (see record 2000-13324-013) discussion of individual differences and optimal development of exceptional talent, and E. Winner's (see record 2000-13324-015) discussion of giftedness. The articles, which have direct implications for the development of talent in children and adults, left J. A. Plucker and J. J. Levy with one serious concern: Practitioners could easily infer that being talented is an overwhelmingly positive experience with little downside. Research suggests otherwise. Plucker and Levy strongly advocate for improvements in the way psychologists and educators develop talent or--more generally--build on individuals' strengths, but any serious discussion of talent development should address strategies that help to mediate the negative consequences of excellence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inverted-U Function Between Salivary Cortisol and Retrieval of Verbal Memory After Hydrocortisone Treatment.

The present study investigated the effect of a single oral dose of hydrocortisone (cortisol) on retrieval of verbal and nonverbal declarative memory. Fifty-nine healthy participants were randomly assigned to either receive 25 mg cortisol or a placebo 45 min before retrieval in a standardized memory test procedure. There was no global effect of cortisol on either verbal or nonverbal memory. However, a specific negative effect on free recall of associative verbal material appeared. In addition, high responders (salivary cortisol concentration > 68.25 nmol/L) exhibited impaired verbal memory compared with low responders (     

Sexual behavior in young adulthood: A population-based twin study.

Objective: With behavior genetic analyses of data from young adult twins, we evaluated theoretical perspectives that differentially emphasize biological dispositions, social/cultural factors, or universal pathways to explain individual differences in sexual behaviors. Design: We fit biometric sex limitation models to three aspects of sexual behavior reported by 4,925 Finnish twins ages 23-27. Main Outcome Measure: From a postal questionnaire, we obtained self-report information on initiation/abstinence of sexual intercourse, onset age, and number of sexual partners. Results: Genetic and non-shared environmental influences were significant for all three measures. There were trends for common environmental influences on initiation and, in females, age at first intercourse. Some differential effects in males and females were found. Results comparing onset age and number of partners among experienced twins from pairs concordant and discordant for initiation found genetic and environmental influences on initiation/abstinence overlapped those found for the other aspects of sexual behavior. Conclusions: These results document genetic variation in individual differences in sexual behavior of young adults. Incorporating genetic dispositions into integrated models of sexual behavior will facilitate more effective health promotion and risk taking intervention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The structure of verbal abilities in young and older adults.

Four language sample measures as well as measures of vocabulary, verbal fluency, and memory span were obtained from a sample of young adults and a sample of older adults. Factor analysis was used to analyze the structure of the vocabulary, fluency, and span measures for each age group. Then an "extension" analysis was performed by using structural modeling techniques to determine how the language sample measures were related to the other measures. The measure of grammatical complexity was associated with measures of working memory including reading span and digit span. Two measures, sentence length in words and a measure of lexical diversity, were associated with the vocabulary measures. The fourth measure, propositional density, was associated with the fluency measures as a measure of processing efficiency. The structure of verbal abilities in young and older adults is somewhat different, suggesting age differences in processing efficiency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Material-specific memory in temporal lobe epilepsy: Effects of seizure laterality and language dominance.

This study investigated the effects of seizure laterality and language dominance on material-specific memory in temporal lobe epilepsy (TLE). Left TLE (LTLE) patients with left-hemisphere language dominance (LHLD) showed significantly higher nonverbal than verbal memory capacity, whereas right TLE patients with LHLD showed significantly better verbal than nonverbal memory capacity. LTLE patients with non-left-hemisphere language dominance (NLHLD) showed significantly better verbal memory capacity compared with LTLE patients with LHLD. Thus, selective verbal or nonverbal memory deficits that are dependent on side of seizure onset were apparent in patients with LHLD but not in patients with NLHLD. Relative sparing of verbal memory capacity in LTLE patients with NLHLD may reflect interhemispheric reorganization of verbal memory function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The inheritance of mental ability.

Arguments "from introspection, from biology, and from neurology" concerning the problem of individual differences in mental ability are cited. The specific independent abilities theory of Thorndike, the single general factor theory of Spearman, and the 2 factors of general and specific abilities are discussed. "In controversies about the facts of mental heredity most critics have tended to assume that the two causal agencies commonly discussed—heredity and environment—are not merely antithetical but mutually exclusive… . In point of fact, with a few rare exceptions, like eye color or serological differences in the blood, every observable characteristic that geneticists have studied has proved to be the product of the joint action of both heredity and environment. There are, in short, no such things as hereditary characters; there are only hereditary tendencies." It is to be regreted that so little progress has been made by psychologists in applying modern genetic methods to fundamental study in the nature-nurture area. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental trajectories in toddlers' self-restraint predict individual differences in executive functions 14 years later: A behavioral genetic analysis.

We examined whether self-restraint in early childhood predicted individual differences in 3 executive functions (EFs; inhibiting prepotent responses, updating working memory, and shifting task sets) in late adolescence in a sample of approximately 950 twins. At ages 14, 20, 24, and 36 months, the children were shown an attractive toy and told not to touch it for 30 s. Latency to touch the toy increased with age, and latent class growth modeling distinguished 2 groups of children that differed in their latencies to touch the toy at all 4 time points. Using confirmatory factor analysis, we decomposed the 3 EFs (measured with latent variables at age 17 years) into a Common EF factor (isomorphic to response inhibition ability) and 2 factors specific to updating and shifting. Less-restrained children had significantly lower scores on the Common EF factor, equivalent scores on the Updating-Specific factor, and higher scores on the Shifting-Specific factor than did the more-restrained children. The less-restrained group also had lower IQ scores, but this effect was entirely mediated by the EF components. Twin models indicated that the associations were primarily genetic in origin for the Common EF variable but split between genetics and nonshared environment for the Shifting-Specific variable. These results suggest a biological relation between individual differences in self-restraint and EFs, one that begins early in life and persists into late adolescence. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The structure of musical preferences: A five-factor model.

Music is a cross-cultural universal, a ubiquitous activity found in every known human culture. Individuals demonstrate manifestly different preferences in music, and yet relatively little is known about the underlying structure of those preferences. Here, we introduce a model of musical preferences based on listeners' affective reactions to excerpts of music from a wide variety of musical genres. The findings from 3 independent studies converged to suggest that there exists a latent 5-factor structure underlying music preferences that is genre free and reflects primarily emotional/affective responses to music. We have interpreted and labeled these factors as (a) a Mellow factor comprising smooth and relaxing styles; (b) an Unpretentious factor comprising a variety of different styles of sincere and rootsy music such as is often found in country and singer–songwriter genres; (c) a Sophisticated factor that includes classical, operatic, world, and jazz; (d) an Intense factor defined by loud, forceful, and energetic music; and (e) a Contemporary factor defined largely by rhythmic and percussive music, such as is found in rap, funk, and acid jazz. The findings from a fourth study suggest that preferences for the MUSIC factors are affected by both the social and the auditory characteristics of the music. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Models of visuospatial and verbal memory across the adult life span.

The authors investigated the distinctiveness and interrelationships among visuospatial and verbal memory processes in short-term, working, and long-term memories in 345 adults. Beginning in the 20s, a continuous, regular decline occurs for processing-intensive tasks (e.g., speed of processing, working memory, and long-term memory), whereas verbal knowledge increases across the life span. There is little differentiation in the cognitive architecture of memory across the life span. Visuospatial and verbal working memory are distinct but highly interrelated systems with domain-specific short-term memory subsystems. In contrast to recent neuroimaging data, there is little evidence for dedifferentiation of function at the behavioral level in old compared with young adults. The authors conclude that efforts to connect behavioral and brain data yield a more complete understanding of the aging mind. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delinquent peer affiliation and conduct problems: A twin study.

Many putative environmental risks correlate with individuals' genotypes. The association between delinquent peer affiliation and conduct problems may occur because of shared genetic liability. Five hundred fifty three monozygotic and 558 dizygotic twin pairs, aged 11 to 18 years, were assessed for delinquent peer affiliation and conduct problems. The authors investigated whether genes contribute to both delinquent peer affiliation and the correlation between delinquent peer affiliations and conduct problems. Delinquent peer affiliation was influenced by genetic, shared environmental, and nonshared environmental factors; genetic factors also contributed to the correlation between delinquent peer affiliations and conduct problems, providing evidence for genotype-environment correlation. The magnitude of the genetic variance of conduct problems was contextually dependent on levels of delinquent peer affiliation and was greater at higher levels of delinquent peer affiliation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The language of online leadership: Gender and youth engagement on the Internet.

This study examines the JUNIOR SUMMIT online community, which consisted of 3,062 adolescents representing 139 countries, varying SES, and a range of experience with computers. The online forum culminated in the election of 100 delegates. By analyzing the messages posted before results of the election were announced, we explore whether language use predicts who was elected as a leader, as well as gender differences in leadership style. Results indicate that the young online leaders do not adhere to adult leadership styles of contributing many ideas, sticking to task, and using powerful language. On the contrary, while the young people elected as delegates do contribute more, their linguistic style is likely to keep the goals and needs of the group as central--by referring to the group rather than to themselves, and by synthesizing the posts of others rather than solely contributing their own ideas. Furthermore, both boy and girl leaders follow this pattern of interpersonal language use. These results reassure us that young people can be civically engaged and community minded, while indicating that these concepts themselves may change through contact with the next generation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Development of Reading in Children Who Speak English as a Second Language.

Patterns of reading development were examined in native English-speaking (L1) children and children who spoke English as a second language (ESL). Participants were 978 (790 L1 speakers and 188 ESL speakers) Grade 2 children involved in a longitudinal study that began in kindergarten. In kindergarten and Grade 2, participants completed standardized and experimental measures including reading, spelling, phonological processing, and memory. All children received phonological awareness instruction in kindergarten and phonics instruction in Grade 1. By the end of Grade 2, the ESL speakers' reading skills were comparable to those of L1 speakers, and ESL speakers even outperformed L1 speakers on several measures. The findings demonstrate that a model of early identification and intervention for children at risk is beneficial for ESL speakers and also suggest that the effects of bilingualism on the acquisition of early reading skills are not negative and may be positive. (PsycINFO Database Record (c) 2010 APA, all rights reserved)