Genetic influence on life events during the last half of the life span.

Genetic influence of perceptions of major events later in life was assessed with a combination of twin and adoption designs as part of the Swedish Adoption/Twin Study of Aging (SATSA). The SATSA design includes 4 groups totaling 399 pairs of same-sex twins: identical and fraternal twins reared apart and matched twins reared together. The average age of the twins was 59 years. The results demonstrate significant genetic influence on reports of the occurrences of life events, especially for controllable events in which the individual can play an active role. Maximum likelihood model-fitting estimates of genetic influence indicate that 40% of the variance of the total life events score is due to genetic differences among individuals. How genetic factors can affect life experiences and directions for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

EAS temperaments during the last half of the life span: Twins reared apart and twins reared together.

In this first behavioral genetic study of personality in the last half of the life span, results are reported using the powerful adoption/twin design that compares identical and fraternal twins reared apart and identical and fraternal twins reared together. Traits studied were the EAS temperaments (emotionality, activity level, and sociability), traits that show substantial genetic influence in childhood. It was hypothesized that the EAS traits would also show significant genetic influence later in life and that most of the environmental variation would be nonshared—that is, twins reared together would show no greater resemblance for the EAS traits than twins reared apart. Both hypotheses are supported. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genetic influence on family environment: The role of personality.

The relation between genetic influence on personality (extraversion and neuroticism) and genetic influence on family environment measures was examined. More than 400 pairs of twins were assessed at the average age of 59 yrs. Trivariate quantitative genetic model-fitting analyses indicated that genetic influence on a Relationship dimension and a Personal Growth dimension of the environmental measure was shared with genetic effects on personality. However, the majority of genetic variance was unique to these measures. The genetic influence on a System Maintenance dimension was largely independent of genetic variance on personality. Taken together, these results suggest that more remains to be explained in the puzzle of genetic influence on environmental measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of sex hormones on obesity across the female life span

Women have a higher prevalence of obesity than men in most developed countries. Obesity affects many aspects of women's health by increasing risk for heart disease, diabetes, breast cancer, and infertility. One reason for the gender difference in obesity may be that fluctuations in reproductive hormone concentrations throughout women's lives uniquely predispose them to excess weight gain. Studies in experimental animals and women have shown that hormonal changes across the menstrual cycle affect calorie and macronutrient intake and alter 24-hour energy expenditure. Pregnancy is a significant factor in the development of obesity for many women. Various factors are associated with excess weight retention following pregnancy, including weight gain during pregnancy, ethnicity, dietary patterns, and interval between pregnancies. There is a need to tailor recommendations for energy intake during pregnancy to individual women, and recent evidence also suggests that the timing of weight gain during pregnancy is a critical factor. Menopause is also a high-risk time for weight gain in women. Although the average woman gains 2-5 pounds during menopausal transition, some women are at risk for greater weight gains. There is also a hormonally driven shift in body fat distribution from peripheral to abdominal at menopause, which may increase health risks in older women. Hormone therapies have varying impacts on body weight and fat distribution. In summary, hormonal fluctuations across the female life span may explain the increased risk for obesity in women. Awareness of these factors allows development of targets for prevention and early intervention.     

Metamemory through the adult life span.

Metamemory is accurate if it returns correct information about the contents in store. It is efficient if it appropriately controls search durations so that more time is allocated to seeking information actually present, and less to information actually absent. 36 adults in 3 age groups (19–22, 44–53, and 65–74 yrs) answered questions on heterogeneous topics, and their responses were timed. Next, metamemorial judgments were made for each S's set of unanswered questions. The same items were then attempted in multiple-choice format, and confidence ratings in the answers were taken. All age groups showed comparable ability to retrieve answers from memory. All showed accurate and efficient metamemory, with no age differences in either. A signal detection analysis raised the possibility that metamemorial sensitivity increases with age. The data also suggest caution among the elderly in suppressing available but low-confidence answers. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Global self-esteem across the life span.

This study provides a comprehensive picture of age differences in self-esteem from age 9 to 90 years using cross-sectional data collected from 326,641 individuals over the Internet. Self-esteem levels were high in childhood, dropped during adolescence, rose gradually throughout adulthood, and declined sharply in old age. This trajectory generally held across gender, socioeconomic status, ethnicity, and nationality (U.S. citizens vs. non-U.S. citizens). Overall, these findings support previous research, help clarify inconsistencies in the literature, and document new trends that require further investigation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Representations of self across the life span.

This research extends a cognitive-developmental approach to examining age differences in self-representation from adolescence to mature adulthood and later life. The authors suggest that mature adults move from representations of self that are relatively poorly differentiated from others or social conventions to ones that involve emphasis on process, context, and individuality. Participants (n men?=?73, n women?=?76), ranging in age from 11 to 85 years, provided spontaneous accounts of their self-representations and responded to measures assessing cognitive and emotional functioning and broad dimensions of personality. On average, self-representation scores peaked in middle-aged adults and were lowest in the preadolescent and older adult age groups. Level of self-representation was related to cognitive and personality variables, but there was some evidence that the pattern of correlates shifted from younger (ages 15–45) to older (ages 46–85) age segments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stability of self-esteem across the life span.

Two studies examined the rank-order stability of self-esteem from age 6 to 83: Study 1 was a meta-analysis of 50 published articles (N = 29,839) and Study 2 analyzed data from 4 large national studies (N = 74,381). Self-esteem showed substantial continuity over time (disattenuated correlations ranged from the .50s to .70s), comparable to the stability found for personality traits. Both studies provided evidence for a robust developmental trend: Self-esteem stability was low during childhood, increased throughout adolescence and young adulthood, and declined during midlife and old age. This trend could not be explained by age differences in the reliability of self-esteem measures, and generally replicated across gender, ethnicity, self-esteem scale, nationality (U.S. vs. non-U.S.), and year of publication. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nature and nurture: Genetic contributions to measures of the family environment.

Research suggests that measures of the family environment show genetic effects when treated as phenotypes in behavioral genetic analyses. This issue was explored as part of the Nonshared Environment in Adolescent Development project using diverse questionnaire measures of parent–child and sibling interactions. The sample consisted of 707 pairs of siblings (aged 10–18 yrs) in a novel design (identical and fraternal twins and full siblings in nondivorced families, and full, half, and unrelated siblings in stepfamilies). Model-fitting analyses yielded evidence for significant genetic effects for 15 of 18 composite measures. On average, more than a quarter of the variance of these environmental measures can be accounted for by genetic differences among children. These results underline the need to investigate the reactive and active organism–environment transactional processes by which genotypes become phenotypes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-concept differentiation across the adult life span.

This study used 2 measures to examine 158 adults' (80 men, 78 women; ages 20 to 88 years) self-concept differentiation (SCD) across 5 role-specific self-representations. Findings revealed that the 2 measures did not assess SCD in similar ways and that they showed different associations with age. Specifically, the 1st measure was not significantly related to age, whereas the 2nd measure showed a curvilinear, U-shaped association with age. The 2nd SCD index also showed significant associations with several measures of emotional adjustment and 6 dimensions of psychological well-being. Additional analyses showed that age moderated the associations between SCD and positive and negative psychological well-being. A high level of SCD was associated with lower positive and higher negative psychological well-being for both young and older adults. However, this effect was significantly more pronounced in older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional experience in everyday life across the adult life span.

Age differences in emotional experience over the adult life span were explored, focusing on the frequency, intensity, complexity, and consistency of emotional experience in everyday life. One hundred eighty-four people, age 18 to 94 years, participated in an experience-sampling procedure in which emotions were recorded across a 1-week period. Age was unrelated to frequency of positive emotional experience. A curvilinear relationship best characterized negative emotional experience. Negative emotions declined in frequency until approximately age 60, at which point the decline ceased. Individual factor analyses computed for each participant revealed that age was associated with more differentiated emotional experience. In addition, periods of highly positive emotional experience were more likely to endure among older people and periods of highly negative emotional experience were less stable. Findings are interpreted within the theoretical framework of socioemotional selectivity theory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Language decline across the life span: Findings from the nun study.

The present study examines language samples from the Nun Study. Measures of grammatical complexity and idea density were obtained from autobiographies written over a 60-year span. Participants who had met criteria for dementia were contrasted with those who did not. Grammatical complexity initially averaged 4.78 ( on a 0-to-7-point scale) for participants who did not meet criteria for dementia and declined .04 units per year; grammatical complexity for participants who met criteria for dementia initially averaged 3.86 and declined .03 units per year. Idea density averaged 5.35 propositions per 10 words initially for participants who did not meet criteria for dementia and declined an average of .03 units per year, whereas idea density averaged 4.34 propositions per 10 words initially for participants who met criteria for dementia and declined .02 units per year. Adult experiences, in general, did not moderate these declines. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Patterns of personality change across the life span.

Six aspects of personality were examined for a sample of 211 individuals across either a 30- or 40-year time span. Latent curve analyses found an underlying pattern of lifetime change for self-confidence, cognitive commitment, outgoingness, and dependability. An underlying pattern of lifetime stability was found for assertiveness. No shared systematic underlying pattern could be fit to individuals' lifetime trajectories for warmth. Although individuals shared a single underlying pattern of change or stability for 5 of the 6 dimensions of personality considered here, they also showed differences in the degree and direction of personality change. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental stability of the relative influence of genes and environment on specific cognitive abilities during childhood.

Describes hierarchical multiple regression (HMR) model for analysis of cross-sectional data to examine developmental changes in the relative influence of genes and environment. The HMR model is advocated because it provides a test of significance for age changes without the loss of information and statistical power that results when continuous variables, such as age, are assigned to categories. This model was applied to 9 tests of specific cognitive abilities that were administered to 54 identical and 33 same-sex fraternal twin pairs whose ages ranged from 5 to 11 yrs. Results indicate that familial influences as well as the relative mixture of genetic and environmental influences on specific cognitive abilities remain stable during this fast-moving developmental era. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of inhibitory control across the life span.

The stop-signal procedure was used to examine the development of inhibitory control. A group of 275 participants, 6 to 81 years of age, performed a visual choice reaction time (go) task and attempted to inhibit their responses to the go task when they heard a stop signal. Reaction times to the stop and go signals were used to assess performance in inhibition and response execution, respectively. Results indicated the speed of stopping becomes faster with increasing age throughout childhood, with limited evidence of slowing across adulthood. By contrast, strong evidence was obtained for age-related speeding of go-signal reaction time throughout childhood, followed by marked slowing throughout adulthood. Hierarchical regression confirmed that the age-related change in inhibitory control could not be explained by general speeding or slowing of responses. Findings are discussed in regard to the contrast between the development of inhibition and response execution and the utility of the stop-signal procedure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differentiation of cognitive abilities across the life span.

Existing representations of cognitive ability structure are exclusively based on linear patterns of interrelations. However, a number of developmental and cognitive theories predict that abilities are differentially related across ages (age differentiation–dedifferentiation) and across levels of functioning (ability differentiation). Nonlinear factor analytic models were applied to multivariate cognitive ability data from 6,273 individuals, ages 4 to 101 years, who were selected to be nationally representative of the U.S. population. Results consistently supported ability differentiation but were less clear with respect to age differentiation–dedifferentiation. Little evidence for age modification of ability differentiation was found. These findings are particularly informative about the nature of individual differences in cognition and about the developmental course of cognitive ability level and structure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impressions of babyfaced individuals across the life span.

Four questions were addressed concerning perceptions of babyfaced individuals from infancy to older adulthood: (1) Do perceivers make reliable babyface judgments at each age; (2) does a babyface have the same effects on trait impressions at each age; (3) are the effects of a babyface independent of the effects of attractiveness; and (4) what facial maturity features are associated with babyface ratings, and do these features predict trait impressions? Ratings of portrait photographs revealed that perceivers reliably detect variations in babyfaceness across the life span. Facial measurements revealed that large eyes, a round face, thin eyebrows, and a small nose bridge characterized a babyface. Trait impressions showed a babyface overgeneralization effect at each age: Babyfaced individuals were perceived to have more childlike traits than their maturefaced peers, and this effect was independent of attractiveness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Presentation and course of major depressive disorder during childhood and later years of the life span

The role of the citric acid cycle enzyme NADP-dependent isocitrate dehydrogenase (IDH-NADP) and its allele product variants in resisting the oxidative agent paraquat, was analyzed among descendants of reciprocal crosses between fast developmental time short-lived individuals (F-) and slow developmental time long-lived ones (S+), in Drosophila melanogaster. Taking preadult developmental time into account, the data suggested that IDH-NADP differences in enzymatic activity between electrophoretically fast and slow allele product variants could play an important role in paraquat resistance and longevity, because individuals with slow developmental time bearing the fast electrophoretic variant of IDH-NADP ("fast" allele) were the most resistant. The fast electrophoretic variant of this enzyme is known to be the most active one and its activity is related to increased reduction of NADP to NADPH. This process could be very important for an effective balance between several pathways that use NADPH as precursor molecules and the oxidative stress defense system that uses it as an oxygen free radical reductor. We also reported a strong maternal effect on these traits, because survivors of a paraquat bioassay carrying cytoplasm inherited from slow developmental long-lived females (S+ cytoplasm) showed the highest frequency of the fast electrophoretical variant of IDH-NADP.     

Egocentrism and social interaction across the life span.

Uses a life-span framework to organize and interpret existing theory and data pertaining to the concept of egocentrism. Review indicates that most research and theorization on egocentrism are concerned with only the infancy and childhood periods of life, although some theorization has concerned the adolescent period. Essentially none of the existing literature pertaining to the major portion of the life span, adulthood and senescence, is directly related to the concept of the egocentrism. However, the notions of rigidity and regression and the process of psychosocial disengagement, all of which have been traditionally identified with the aging process, are reinterpreted as either manifestations of or contributors to increasing egocentricity in later life. Several areas of pertinent research are identified. (119 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)