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Developmental Trajectories (developmental + trajectory)
Kinds of Developmental Trajectories Selected AbstractsDevelopmental Trajectories of Impulsivity and Their Association With Alcohol Use and Related Outcomes During Emerging and Young Adulthood IALCOHOLISM, Issue 8 2010Andrew K. Littlefield Background:, Research has documented normative patterns of personality change during emerging and young adulthood that reflect decreases in traits associated with substance use, such as impulsivity. However, evidence suggests variability in these developmental changes. Methods:, This study examined trajectories of impulsivity and their association with substance use and related problems from ages 18 to 35. Analyses were based on data collected from a cohort of college students (N = 489), at high and low risk for AUDs, first assessed as freshmen at a large, public university. Results:, Mixture modeling identified five trajectory groups that differed in baseline levels of impulsivity and developmental patterns of change. Notably, the trajectory group that exhibited the sharpest declines in impulsivity tended to display accelerated decreases in alcohol involvement from ages 18 to 25 compared to the other impulsivity groups. Conclusion:, Findings highlight the developmental nature of impulsivity across emerging and young adulthood and provide an empirical framework to identify key covariates of individual changes of impulsivity. [source] Developmental Trajectories of Sex-Typed Behavior in Boys and Girls: A Longitudinal General Population Study of Children Aged 2.5,8 YearsCHILD DEVELOPMENT, Issue 5 2008Susan Golombok The stability of sex-typed behavior from the preschool to the middle school years was examined. The Preschool Activities Inventory, a measure of within-sex variation in sex-typed behavior, was completed by the primary caregiver when the child was 2.5, 3.5, and 5 years, and a modified version, the Child Activities Inventory, was completed by the child at age 8. The investigation involved a general population sample of 2,726 boys and 2,775 girls. Sex-typed behavior increased through the preschool years, and those children who were the most sex typed at age 2.5 were still the most sex typed at age 5, with those children who showed the highest levels of sex-typed behavior during the preschool years continuing to do so at age 8. [source] The Relation of Preschool Child-Care Quality to Children's Cognitive and Social Developmental Trajectories through Second GradeCHILD DEVELOPMENT, Issue 5 2001Ellen S. Peisner-Feinberg The cognitive ad socioemotional development of 733 children was examined longitudinally from ages 4 to 8 years as a function of the quality of their preschool experiences in community child-care centers, after adjusting for family selection factors related to child-care quality and development. These results provide evidence that child-care quality has a modest long-term effect on children's patterns of cognitive and socioemotional development at least through kindergarten, and in some cases, through second grade. Differential effects on children's development were found for two aspects of child-care quality. Observed classroom practices were related to children's language and academic skills, whereas the closeness of the teacher , child relationship was related to both cognitive and social skills, with the strongest effects for the latter. Moderating influences of family characteristics were observed for some outcomes, indicating stronger positive effects of child-care quality for children from more at-risk backgrounds. These findings contribute further evidence of the long-term influences of the quality of child-care environments on children's cognitive and social skills through the elementary school years and are consistent with a bioecological model of development that considers the multiple environmental contexts that the child experiences. [source] Longitudinal course of anxiety in children and adolescents with Williams syndrome,AMERICAN JOURNAL OF MEDICAL GENETICS, Issue 2 2010Janet Woodruff-Borden Abstract The longitudinal course of anxiety disorders in 45 children and adolescents with Williams syndrome (WS) was examined. Children were ages 4,13 years at the initial assessment. To assess their child's DSM-IV diagnoses, parents completed a structured diagnostic interview 3,9 times at intervals of at least 1 year. At the first assessment, 60% of the sample presented with at least one anxiety diagnosis; 82.2% received an anxiety diagnosis at some time during the study. Chronic, persistent anxiety within the period 5 years after their initial diagnosis was shown by 62.2% of those with an anxiety diagnosis (51.1% of the entire sample). The most common diagnoses were specific phobias and generalized anxiety disorder. Multilevel logistic regression models were estimated for the presence of any anxiety disorder, specific phobia, and specific phobia of loud noises. Developmental trajectories, expressed as the probability of a positive diagnosis, suggested that the odds of a positive diagnosis did not change with age. IQ was not significantly related to the presence of an anxiety disorder. However, there was a significant relation between executive functioning and anxiety such that the presence of an anxiety diagnosis was associated with increased scores on behavioral regulation, indicative of increased difficulty with inhibitory control of affect and behavior. These findings are discussed in terms of persistence of anxiety over time and the need to develop and test interventions to address the high levels of anxiety experienced by children and adolescents with WS. © 2010 Wiley-Liss, Inc. [source] The antecedents of non-affective psychosis in a birth-cohort, with a focus on measures related to cognitive ability, attentional dysfunction and speech problemsACTA PSYCHIATRICA SCANDINAVICA, Issue 4 2010J. Welham Welham J, Scott J, Williams GM, Najman JM, Bor W, O'Callaghan M, McGrath J. The antecedents of non-affective psychosis in a birth-cohort, with a focus on measures related to cognitive ability, attentional dysfunction, and speech problems. Objective:, Adults with non-affective psychosis show subtle deviations in a range of developmental trajectories as children and adolescents. Method:, Based on a birth-cohort (n = 3801), we examined the Peabody Picture Vocabulary Test (PPTV) at age 5, and Raven's Standard Progressive Matrices (RSPM) and Wide Range Achievement Test reading scale (WRAT-R) at age 14. Items related to speech problems and attentional dysfunction were available from maternal- or self-report. At age 21, we identified 60 cohort members who were screen-positive for non-affective psychosis (SP-NAP). Results:, Impaired performance on the PPVT and RSPM (but not WRAT-R) predicted SP-NAP for males only. Male cohort members in the highest quartile for attentional dysfunction at ages 5 and 14 were about 5,8 times more likely to develop SP-NAP. SP-NAP in males was significantly associated with speech problems at age 14. Conclusion:, Males who develop non-affective psychoses have subtle impairments in cognitive capacity prior to the development of their psychotic disorder. [source] Delayed axonal pruning in the ant brain: A study of developmental trajectoriesDEVELOPMENTAL NEUROBIOLOGY, Issue 6 2009Marc A. Seid Abstract The coordination of neuronal maturation and behavioral development is a vital component of survival. The degradation of excessive axonal processes and neuronal networks is a ubiquitous developmental process. In Drosophila, a great portion of axonal pruning occurs during metamorphosis and transpires within hours after pupation. In contrast, we show, using EM-serial sectioning and 3D-reconstructions, that axonal pruning occurs after eclosion and over the course of 60 days in Cataglyphis albicans. Using the mushroom bodies of the brains of Cataglyphis, which have well-developed lip (olfactory integrator) and collar (visual integrator) regions, we show that axonal pruning is dependent upon the differences in the developmental trajectory of the lip and the collar brain regions and happens after eclosion. The elimination of the axonal boutons is most delayed in the collar region, where it is postponed until the ant has had extensive visual experience. We found that individual brain components within a single neuropil can develop at different rates that correlate with the behavioral ecology of these ants and suggest that glia may be mediating the axonal pruning. Our study provides evidence that adult ants may have relatively neotenous brains, and thus more flexibility, allowing them to neuronally adapt to the environment. This neoteny may, in part, explain the neural basis for age-dependent division of labor and the amazing behavioral flexibility exhibited by ants. © 2009 Wiley Periodicals, Inc. Develop Neurobiol, 2009 [source] Differential development of body equilibrium among littermates in the newborn rabbitDEVELOPMENTAL PSYCHOBIOLOGY, Issue 1 2009Edith Muciño Abstract Interest is growing among psychobiologists and behavioral ecologists in the role of sibling relations in shaping individual development and life histories. In litters of domestic rabbits Oryctolagus cuniculus the heaviest pups at birth are more likely to survive the critical first postnatal week, they compete more effectively with littermates for milk and well-insulated positions in the litter huddle, and are the heaviest at weaning. Here we report that high birth weight pups are also better able to maintain body equilibrium. Testing pups' ability to maintain equilibrium when placed on a 15° ramp for 2 min each day during the first postnatal week, we found that pups showed a continual daily improvement in their ability to maintain balance while moving on the ramp, rarely lost balance by postnatal day 8, and that heavier pups could maintain balance better and earlier than their lighter littermates. Better ability to maintain body equilibrium, however achieved, may help explain heavier pups' advantage in competing for vital resources such as milk and in gaining access to better-insulated positions in the litter huddle. It also provides further support for the usefulness of birth weight, not only as an absolute measure but also relative to the weight of other littermates, as a predictor of different developmental trajectories, behavioral and physiological, among same-age siblings in this mammal. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 51: 24,33, 2009 [source] Development of using experimenter-given cues in infant chimpanzees: longitudinal changes in behavior and cognitive developmentDEVELOPMENTAL SCIENCE, Issue 1 2008Sanae Okamoto-Barth The use of gaze shifts as social cues has various evolutionary advantages. To investigate the developmental processes of this ability, we conducted an object-choice task by using longitudinal methods with infant chimpanzees tested from 8 months old until 3 years old. The experimenter used one of six gestures towards a cup concealing food; tapping, touching, whole-hand pointing, gazing plus close-pointing, distant-pointing, close-gazing, and distant-gazing. Unlike any other previous study, we analyzed the behavioral changes that occurred before and after choosing the cup. We assumed that pre-choice behavior indicates the development of an attentional and spatial connection between a pointing cue and an object (e.g. Woodward, 2005); and post-choice behavior indicates the emergence of object permanence (e.g. Piaget, 1954). Our study demonstrated that infant chimpanzees begin to use experimenter-given cues with age (after 11 months of age). Moreover, the results from the behavioral analysis showed that the infants gradually developed the spatial link between the pointing as an object-directed action and the object. Moreover, when they were 11 months old, the infants began to inspect the inside of the cup, suggesting the onset of object permanence. Overall, our results imply that the ability to use the cues is developing and mutually related with other cognitive developments. The present study also suggests what the standard object-choice task actually measures by breaking the task down into the developmental trajectories of its component parts, and describes for the first time the social-physical cognitive development during the task with a longitudinal method. [source] Switching between spatial stimulus,response mappings: a developmental study of cognitive flexibilityDEVELOPMENTAL SCIENCE, Issue 4 2004Eveline A. Crone Four different age groups (8,9-year-olds, 11,12-year-olds, 13,15-year-olds and young adults) performed a spatial rule-switch task in which the sorting rule had to be detected on the basis of feedback or on the basis of switch cues. Performance errors were examined on the basis of a recently introduced method of error scoring for the Wisconsin Card Sorting Task (WCST; Barcelo & Knight, 2002). This method allowed us to differentiate between errors due to failure-to-maintain-set (distraction errors) and errors due to failure-to-switch-set (perseverative errors). The anticipated age differences in performance errors were most pronounced for perseverative errors between 8,9 years and 11,12 years, but for distraction errors adult levels were not reached until 13,15 years. These findings were interpreted to support the notion that set switching and set maintenance follow distinct developmental trajectories. [source] Deviations in the emergence of representations: a neuroconstructivist framework for analysing developmental disordersDEVELOPMENTAL SCIENCE, Issue 1 2000Andrew Oliver A common way of studying developmental disorders is to adopt a static neuropsychological deficit approach, in which the brain is characterized in terms of a normal brain with some parts or ,modules' impaired. In this paper we outline a neuroconstructivist approach in which developmental disorders are viewed as alternative developmental trajectories in the emergence of representations within neural networks. As a concrete instantiation of the assumptions underlying this general approach, we present a number of simulations in an artificial neural network model. The representations that emerge under different architectural, input and developmental timing conditions are then analysed within a multi-dimensional state space. We explore alternative developmental trajectories in these simulations, demonstrating how initial differences in the same parameter can lead to very different outcomes, and conversely how different starting states can sometimes result in similar end states (phenotypes). We conclude that the assumptions of the neuroconstructivist approach are likely to be more appropriate for analysing developmental deviations in complex dynamic neural networks, such as the human brain. [source] Black youth, identity, and ethicsEDUCATIONAL THEORY, Issue 1 2005Garrett Albert Duncan This article examines stage models of racial identity that researchers and educators use to explain the subjective processes that influence how black youth navigate school. Despite the explicit challenge that most models of racial identity have posed to racist discourses in the research literature, the underlying ethics of their developmental trajectories is constrained by a politics of respectability that subverts a larger project of affirming black humanity. I use interview data to propose an alternative model for how black adolescent identity is formed. I conclude with a discussion of the importance of rethinking black adolescence in the context of changes in communication technologies associated with postindustrialism and globalization. [source] A developmental typology of adolescent personalityEUROPEAN JOURNAL OF PERSONALITY, Issue 4 2010Theo A. Klimstra Abstract The purpose of the current study is to examine whether Block's personality types (i.e. Resilients, Undercontrollers and Overcontrollers) are replicable as developmental trajectories. We applied a Latent Class Growth Analysis (LCGA) framework to five- annual-wave data on a sample of early to middle adolescents (n,=,923). Our results showed that Block's Resilients, Undercontrollers and Overcontrollers are indeed replicable as developmental trajectories across adolescence. These developmental types were related to problem behaviour in a similar way as types found in studies using cross-sectional data. As such, Resilients reflected low levels of problem behaviour, Undercontrollers had high levels of delinquency and Overcontrollers had high levels of depression. Implications and suggestions for further research are discussed. Copyright © 2009 John Wiley & Sons, Ltd. [source] The personality-identity interplay in emerging adult women: convergent findings from complementary analysesEUROPEAN JOURNAL OF PERSONALITY, Issue 3 2006Koen Luyckx Abstract The present study examined whether identity development occurs in tandem with personality development in emerging adulthood. Three-wave longitudinal data on a sample of 351 female college students were used to answer questions about stability and change, direction of effects, and interrelated developmental trajectories. Four identity dimensions (i.e. commitment making, exploration in breadth, identification with commitment, and exploration in depth) and the Big Five were assessed. Identity and personality were found to be meaningfully related at the level of both the time-specific adjacent measures and the underlying developmental trajectories with various degrees of convergence. Cross-lagged analyses substantiated reciprocal influences and Latent Growth Curve Modelling substantiated common developmental pathways that partially mirrored the concurrent relations. Implications and suggestions for future research are discussed. Copyright © 2006 John Wiley & Sons, Ltd. [source] Examining the Lives of Navajo Native American Teenage Mothers in Context: A 12- to 15-Year Follow-UpFAMILY RELATIONS, Issue 2 2009Rochelle L. Dalla In 1992 and 1995, data were collected from 29 Navajo, reservation-residing teenage mothers. In 2007, follow-up data from 69% (n= 20) of the original sample were collected. Intensive interviews, grounded in ecological systems theory (U. Bronfenbrenner, 1989), allowed for contextual examination of the women's developmental trajectories. Significant educational accomplishments and a strong work ethic (i.e., individual level) exemplified the majority of respondents. Relationships with families of origin and intimate partners (i.e., microsystems) and connections between these (i.e., mesosystems) promoted and challenged participants' optimal development and were significantly influenced by macrosystem factors (e.g., economic constraints, physical isolation). Implications for service provision and continued research are discussed. [source] Comparison of developmental trajectories in the starlet sea anemone Nematostella vectensis: embryogenesis, regeneration, and two forms of asexual fissionINVERTEBRATE BIOLOGY, Issue 2 2007Adam M. Reitzel Abstract. The starlet sea anemone, Nematostella vectensis, is a small burrowing estuarine animal, native to the Atlantic coast of North America. In recent years, this anemone has emerged as a model system in cnidarian developmental biology. Molecular studies of embryology and larval development in N. vectensis have provided important insights into the evolution of key metazoan traits. However, the adult body plan of N. vectensis may arise via four distinct developmental trajectories: (1) embryogenesis following sexual reproduction, (2) asexual reproduction via physal pinching, (3) asexual reproduction via polarity reversal, and (4) regeneration following bisection through the body column. Here, we compare the ontogenetic sequences underlying alternate developmental trajectories. Additionally, we describe the predictable generation of anomalous phenotypes that can occur following localized injuries to the body column. These studies suggest testable hypotheses on the molecular mechanisms underlying alternate developmental trajectories, and they provoke new questions about the evolution of novel developmental trajectories and their initiation via environmental cues. [source] Testing the developmental distinctiveness of male proactive and reactive aggression with a nested longitudinal experimental interventionAGGRESSIVE BEHAVIOR, Issue 2 2010Edward D. Barker Abstract An experimental preventive intervention nested into a longitudinal study was used to test the developmental distinctiveness of proactive and reactive aggression. The randomized multimodal preventive intervention targeted a subsample of boys rated disruptive by their teachers. These boys were initially part of a sample of 895 boys, followed from kindergarten to 17 years of age. Semiparametric analyses of developmental trajectories for self-reported proactive and reactive aggression (between 13 and 17 years of age) indicated three trajectories for each type of aggression that varied in size and shape (Low, Moderate, and High Peaking). Intent-to-treat comparisons between the boys in the prevention group and the control group confirmed that the preventive intervention between 7 and 9 years of age, which included parenting skills and social skills training, could impact the development of reactive more than proactive aggression. The intervention effect identified in reactive aggression was related to a reduction in self-reported coercive parenting. The importance of these results for the distinction between subtypes of aggressive behaviors and the value of longitudinal-experimental studies from early childhood onward is discussed. Aggr. Behav. 36:127,140, 2010. © 2010 Wiley-Liss, Inc. [source] Continuity and change in social and physical aggression from middle childhood through early adolescenceAGGRESSIVE BEHAVIOR, Issue 5 2009Marion K. Underwood For a sample followed from age 9,13 (N=281), this investigation examined developmental trajectories for social and physical aggression as measured by teacher ratings. Trajectories for both forms of aggression were estimated first separately, then jointly. Mean levels of both social and physical aggression decreased over time for the overall sample, but with high variability of individual trajectories. Subgroups followed high trajectories for both social and physical aggression. Joint estimation yielded six trajectories: low stable, low increasers, medium increasers, medium desisters, high desisters, and high increasers. Membership in the high increaser group was predicted by male gender, unmarried parents, African American ethnicity, and maternal authoritarian and permissive parenting. Permissive parenting also predicted membership in the medium increaser group. This is one of the first studies to examine social aggression longitudinally across this developmental period. Though the results challenge the claim that social aggression is at its peak in early adolescence, the findings emphasize the importance of considering different developmental trajectories in trying to understand origins and outcomes of aggression. Aggr. Behav. 35:357,375, 2009. © 2009 Wiley-Liss, Inc. [source] Development and validation of the Subtypes of Antisocial Behavior QuestionnaireAGGRESSIVE BEHAVIOR, Issue 5 2009S. Alexandra Burt Abstract There is converging evidence that physical aggression, rule-breaking, and social aggression constitute meaningfully distinct, if somewhat overlapping, components of the broader construct of antisocial behavior. Indeed, these subtypes appear to have different developmental trajectories, demographic correlates, and personological underpinnings. They also demonstrate important etiological distinctions. One potential limitation to accumulating additional scientific insights into the correlates and origins of these three types of antisocial behavior is the lack of an efficient self-report assessment in the public domain. We developed the 32-item Subtypes of Antisocial Behavior Questionnaire (STAB) to fill this gap. Our goal was to develop a brief measure that could reliably and validly assess each of the three major subtypes of antisocial behavior and that would be freely available for other researchers. The present series of studies provides initial evidence of the factorial validity, internal consistency, and criterion-related validity of the STAB scales. In short, it appears that the STAB is a brief and useful measure that can be used to differentiate and assess physically aggressive, rule-breaking, and socially aggressive forms of antisocial behavior. Aggr. Behav. 35:376,398, 2009. © 2009 Wiley-Liss, Inc. [source] ,Poor children grow into poor adults': harmful mechanisms or over-deterministic theory?JOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 8 2002Shahin Yaqub Does childhood poverty lead to adult poverty? Evidence shows childhood is a sensitive period for developing cognition, physical vitality and personality. This is traceable to specific behavioural and biological mechanisms. However such science could easily drive over-deter ministic views about how childhood affects later life. The paper therefore discusses how damage from childhood poverty can,at least sometimes and partially,be resisted or reversed, both during childhood and in adulthood. As people reach biological maturity, alterations to their developmental trajectories rely increasingly on alterations in behavioural relationships. Opportunities remain vital throughout life for sustained socioeconomic attainment. Copyright © 2002 John Wiley & Sons, Ltd. [source] Development of Mathematics Interest in Adolescence: Influences of Gender, Family, and School ContextJOURNAL OF RESEARCH ON ADOLESCENCE, Issue 2 2010Anne C. Frenzel This study investigated adolescents' developmental trajectories of mathematics interest and explored related effects of gender, family, and school context. Latent growth curve modeling was used to analyze longitudinal data of N=3,193 students (51% female) from grades 5 to 9 from all 3 ability tracks of the German state school system. Annual assessments involved student questionnaires on interest in mathematics, perceptions of classroom characteristics (classroom values for mathematics, mathematics teacher enthusiasm), as well as parent questionnaires regarding family values for mathematics. Results indicated a downward trend of students' mathematics interest that plateaued in later years, with high variability in mean levels, but little variability in the shape of the growth trajectories. Boys reported higher mathematics interest than girls, but similar downward growth trajectories. Students from the lowest ability track showed more favorable interest trajectories than students from the middle and highest tracks. Family values and classroom characteristics were positively related to within-person levels of interest over time and to average individual levels of interest, but not to growth parameters. Theoretical and practical implications are discussed. [source] Individual and ecological assets and positive developmental trajectories among gang and community-based organization youthNEW DIRECTIONS FOR YOUTH DEVELOPMENT, Issue 95 2002Carl S. Taylor The Search Institute framework for conceptualizing developmental assets was used in a longitudinal study of African American male youth involved in gangs or in community-based organizations (CBOs) serving youth. Analyses of intraindividual change indicated that individual and ecological assets are linked to positive developmental trajectories among these youth. [source] Are cortisol profiles a stable trait during child development?AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 6 2009Mark V. Flinn Exposure to stressful experiences can increase vulnerability to adverse health outcomes. A potential neuroendocrine mechanism mediating the link between stress and health is the hypothalamic-pituitary-adrenal (HPA) system, with a key role attributed to the glucocorticoid hormone cortisol. Retrospective and cross sectional clinical studies of humans and experimental studies with nonhuman primates and rodents suggest that traumatic experiences during critical periods in development may have permanent effects on HPA regulation, which in turn can have deleterious effects on health. Here I report results from a continuous 20-year study (1988,2009) of children in a rural community on Dominica. Sequential data on cortisol levels, social stressors, and health in naturalistic, everyday conditions are examined to assess developmental trajectories of HPA functioning. Saliva aliquots were assayed for cortisol in concert with monitoring of growth, morbidity, and social environment. Analyses here include data from 1989 to 1999 for 147 children aged 3,16 years with >100 saliva samples each. Cortisol values were standardized by elapsed time since wake-up. Results do not support the hypothesis that traumatic stress during childhood causes permanent general elevation of cortisol levels. Am. J. Hum. Biol., 2009. © 2009 Wiley-Liss, Inc. [source] Developmental changes in the relationship between leptin and adiposity among Tsimané children and adolescentsAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 4 2008Katherine C. B. Sharrock Leptin is thought to signal energy stores, thus helping the body balance energy intake and expenditure. However, the strong relationship between leptin and adiposity in populations with adequate nutrition or common obesity is not universal across ecologic contexts, and leptin often correlates only weakly, or not at all, with adiposity in populations of lean or marginally-nourished males. To clarify whether the relationship between adiposity and leptin changes during development, this study examines leptin and body fat among children and adolescents of lowland Bolivia. Anthropometric measures of body composition and dried blood spot samples were collected from 487 Tsimane' ranging from 2 to 15 years of age. Leptin was assayed using an enzyme immunoassay protocol validated for use with blood spot samples. In this population, leptin concentrations were among the lowest reported in a human population (mean ± SD: 1.26 ± 0.5 and 0.57 ± 0.3 in females and males). In addition, the relationship between leptin and adiposity follows distinct developmental trajectories in males and females. In males, leptin is weakly correlated with most measures of body composition at all ages investigated. However, in females, the level of body fat and the strength of the correlation between body fat and leptin (a measure of its strength as a signal of energy stores) both increase markedly with age. These findings suggest a more important role of leptin as a signal of energy stores among females as they approach reproductive maturity, while raising questions about the function of this hormone in lean males. Am. J. Hum. Biol., 2008. © 2008 Wiley-Liss, Inc. [source] The ontogeny of Holocene and Late Pleistocene human postcranial strengthAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2010Libby W. Cowgill Abstract While a wide variety of studies have focused on population variation in adult cross-sectional properties, relatively little is known about population variation in postcranial robusticity in immature individuals. Furthermore, the age at which the population differences readily detected in adults manifest during growth is also unknown. This research addresses these gaps in our current understanding through the analysis of immature humeral and femoral long bone strength. Cross-sectional geometry was used to compare the developmental trajectories of diaphyseal strength in Late Pleistocene Neandertal and modern human subadults to a sample of immature humans from seven geographically diverse Holocene populations. Population differences in size-standardized cross-sectional properties appear to be systemic and develop very early in ontogeny in the Holocene sample. In many cases, these differences are present before one year of age. In general, the Late Pleistocene fossil samples fit within the range of recent human variation in long bone strength. Population differences detected here are likely related to a combination of factors including activity patterns, genetic propensities, and nutritional status. These results highlight the complex mosaic of processes that result in adult postcranial robusticity, and suggest that further exploration of the developmental interplay between intrinsic and extrinsic influences on skeletal robusticity will likely enhance our understanding of adult postcranial morphology. Am J Phys Anthropol 2010. © 2009 Wiley-Liss, Inc. [source] Personality Risk Factors Associated with Trajectories of Tobacco UseTHE AMERICAN JOURNAL ON ADDICTIONS, Issue 6 2006Judith S. Brook EdD The purpose of this longitudinal, prospective study was to evaluate trajectories of smoking in a cohort of African-American and Puerto Rican young adults and describe personality and behavioral factors associated with specific smoking trajectory group membership. Participants consisted of African-American and Puerto Rican male and female young adults (n = 451, mean age 26) from an inner-city community. Data were collected at four time points over a period of 13 years using structured interviews. Interviews took place within the schools and the participants' homes. Scales with adequate psychometric properties were adapted from previously validated measures. Variables that were examined for this study came from the domains of internalizing behaviors, externalizing behaviors, drug use, and demographic information. Data were analyzed using latent growth mixture modeling to explore discrete smoking trajectories. Logistic regression analyses were then used to examine the risk factors associated with the various smoking trajectory groups. Four trajectory groups were determined to best fit the data: nonsmokers, maturing-out smokers, late-starting smokers, and early-starting continuous smokers. Subjects who were unconventional, experienced intrapersonal distress, and used alcohol and illegal drugs were more likely to belong to one of the smoking trajectory groups than to the nonsmoking group. The early-starting continuous group scored highest on these personal risk attributes. The long-term impact of unconventional behavior, intrapersonal distress, and drug use on developmental trajectories of smoking support the importance of early intervention and prevention. [source] Using behavior to determine immature life-stages in captive western gorillasAMERICAN JOURNAL OF PRIMATOLOGY, Issue 6 2010J.E. Hutchinson Abstract Ontogenic development is divided into infant, juvenile, adolescent and adult life-stages. Although the developmental trajectory of an individual is a flexible entity, which differs within species, environment and sex, life-stage classifications are generally structured, age-based systems. This invariably leads to rigidity within a dynamic system and consequently hampers our understanding of primate life history strategies. We propose that life-stage classifications should be quantitative, flexible entities, which use a reliable measurement of development. Here, we provide a methodological example where placement into a life-stage is based upon behavioral variance between other similar-aged individuals. Behavioral data were collected from 12 male (3,11 years old) and 9 female (3,8 years old) captive immature western gorillas (Gorilla gorilla gorilla) housed in five family groups, using continuous focal sampling; 900,hr of data were collected over 131 days. Data were applied to four published life-stage classifications for mountain gorillas (Gorilla beringei beringei), which showed variable ability to determine life-stage in western gorillas. A new life-stage classification (Hutchinson & Fletcher) was proposed specifically for western gorillas, whereby multiple co-varying behavior provided a robust measure of linear development across immaturity. Each life-stage was found to be a distinct ontogenic phase and the classification discriminated life-stage with a high level of accuracy. Using the Hutchinson & Fletcher classification we provide evidence for disparity in developmental trajectories between the sexes from the juvenile period onwards. To expand the understanding of primate life histories, we propose that flexible classifications should be used to enable comparison of allometric life history traits within and between species, from birth onwards. Am. J. Primatol. 72:492,501, 2010. © 2010 Wiley-Liss, Inc. [source] Developmental origins of disruptive behaviour problems: the ,original sin' hypothesis, epigenetics and their consequences for preventionTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 4 2010Richard E. Tremblay This paper reviews publications on developmental trajectories of disruptive behaviour (DB) problems (aggression, opposition-defiance, rule breaking, and stealing-vandalism) over the past decade. Prior to these studies two theoretical models had strongly influenced research on DB: social learning and disease onset. According to these developmental perspectives, children learn DB from their environment and onset of the disease is triggered by accumulated exposition to disruptive models in the environment, including the media. Most of the evidence came from studies of school age children and adolescents. Longitudinal studies tracing developmental trajectories of DB from early childhood onwards suggest an inversed developmental process. DB are universal during early childhood. With age, children learn socially acceptable behaviours from interactions with their environment. A ,disease' status is given to children who fail to learn the socially acceptable behaviours. The mechanisms that lead to deficits in using socially accepted behaviours are strongly intergenerational, based on complex genetic and environmental contributions, including epigenetic mechanisms. Prevention of these deficits requires early, intensive and long-term support to parents and child. Newly discovered epigenetic mechanisms suggest that intensive perinatal interventions will have impacts on numerous aspects of physical and mental health, including DB. This review also concludes that: a) subtypes of disruptive behaviours should not be aggregated because they have different developmental trajectories and require specific corrective interventions; b) the overt,covert and destructive,nondestructive dimensions appear the most useful to create DB subtypes; c) overt DB onset before covert DB because the latter require more brain maturation; d) DB subtype taxonomies are more useful for clinicians than developmental taxonomies because the latter are post mortem diagnoses and clinicians' retrospective information is unreliable; e) we need large-scale collaborative preventive experimental interventions starting during early pregnancy to advance knowledge on causes and prevention of DB problems. [source] Depression and anxiety symptoms: onset, developmental course and risk factors during early childhoodTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 10 2009Sylvana M. Côté Background:, Depressive and anxiety disorders are among the top ten leading causes of disabilities. We know little, however, about the onset, developmental course and early risk factors for depressive and anxiety symptoms (DAS). Objective:, Model the developmental trajectories of DAS during early childhood and to identify risk factors for atypically high DAS. Method:, Group-based developmental trajectories of DAS conditional on risk factors were estimated from annual maternal ratings (1½ to 5 years) in a large population sample (n = 1759). Results:, DAS increased substantially in two of the three distinct trajectory groups identified: High-Rising (14.7%); Moderate-Rising (55.4%); and Low (29.9%). Two factors distinguished the High-Rising group from the other two: Difficult temperament at 5 months (High-Rising vs Moderate-Rising: OR = 1.32; 95% CI = 1.13,1.55; High-Rising vs Low: OR = 1.31, CI = 1.12,1.54) and maternal lifetime major depression (High-Rising vs Moderate-Rising: OR = 1.10; CI = 1.01,1.20; High-Rising vs Low: OR = 1.19; CI = 1.08,1.31). Two factors distinguished the High-Rising group from the Low group: High family dysfunction (OR = 1.24; CI = 1.03,1.5) and Low parental self-efficacy (OR = .71; CI = .54,.94). Conclusions:, DAS tend to increase in frequency over the first 5 years of life. Atypically high level can be predicted from mother and child characteristics present before 6 months of age. Preventive interventions should be experimented with at risk infants and parents. [source] Research review: A critical review of studies on the developmental trajectories of antisocial behavior in femalesTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 4 2009Nathalie Fontaine Background:, Knowledge on the onset and the development of antisocial behavior in females is limited, because most of the research in this domain is based on males. Methods:, We critically reviewed 46 empirical studies that examined developmental trajectories of antisocial behavior in females, notably to help determine whether or not an early-onset/life-course-persistent trajectory exists in females. Results:, The review suggested that antisocial behavior in females can follow different developmental trajectories (e.g., early-onset/life-course-persistent, childhood-limited, adolescence-limited, adolescence-delayed-onset, adulthood-onset). However, many of the studies reviewed were limited by factors such as the use of global measures of antisocial behavior, the identification of the trajectories based on threshold criteria, and the small sample sizes. Conclusions:, Future studies should take into account the shortcomings highlighted in this review. Such studies are needed to improve the understanding and prevention of the development of antisocial behavior in females. [source] The future of psychotherapy for mentally ill children and adolescentsTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 1-2 2009John S. March Objective:, Given striking advances in translational developmental neuroscience and its convergence with developmental psychopathology and developmental epidemiology, it is now clear that mental illnesses are best thought of as neurodevelopmental disorders. This simple fact has enormous implications for the nature and organization of psychotherapy for mentally ill children, adolescents and adults. Method:, This article reviews the ,trajectory' of psychosocial interventions in pediatric psychiatry, and makes some general predictions about where this field is heading over the next several decades. Results:, Driven largely by scientific advances in molecular, cellular and systems neuroscience, psychotherapy in the future will focus less on personal narratives and more on the developing brain. In place of disorders as intervention targets, modularized psychosocial treatment components derived from current cognitive-behavior therapies will target corresponding central nervous system (CNS) information processes and their functional behavioral consequences. Either preventive or rehabilitative, the goal of psychotherapy will be to promote development along typical developmental trajectories. In place of guilds, psychotherapy will be organized professionally much as physical therapy is organized today. As with other forms of increasingly personalized health care, internet-based delivery of psychotherapy will become commonplace. Conclusion:, Informed by the new field of translational developmental neuroscience, psychotherapy in the future will take aim at the developing brain in a service delivery model that closely resembles the place and role of psychosocial interventions in the rest of medicine. Getting there will be, as they say, interesting. [source] | |||||||||||||||||||