<p>Puberty is the process of becoming sexually mature and it has fundamental somatic and psychosocial implications. The focus of this dissertation was the short and long term developmental significance, concerning both soma et psyche, of female pubertal timing. Four studies were designed to accomplish these aims. Six samples of different ages from different countries and from different time points, comprising several thousand females some of which were followed longitudinally, were used. Age at menarche was used as the primary measure of pubertal maturation. The first main aim of this dissertation was to explore the mechanisms that might explain the well-established link between female pubertal timing and problem behavior, and to identify contextual conditions at which associations are stronger or weaker. Existing explanations are unsatisfactory and little is known about conditions that might affect the strength of the associations.</p><p>In Paper I, we tested and confirmed a peer socialization hypothesis as a satisfactory explanation for the link between early puberty and problematic adjustment. In short, this hypothesis posits that early developing girls associate with older peers and boyfriends because they feel more mature than their same age peers, and through these peers and boyfriends the early developed girls are channeled into more socially advanced behaviors, including normbreaking. This should be particularly true in contexts where heterosexual relationships are sanctioned and where there is an abundance of deviant youth. In Paper II, I used a biopsychosocial approach and studied pubertal timing along with self-perceptions of maturity and early romantic relationships. The findings revealed that early puberty had very different implications depending on the psychological and social contexts in which it was embedded. For instance, when early puberty was coupled with feeling mature and having early romantic relationships, it was associated with adjustment problems. When early puberty was coupled with neither, it was not linked to particularly high levels of problem behavior.</p><p>In stark contrast to the vast literature on the role of female pubertal timing in adolescence, the literature on long-term implications is remarkably limited. For this reason, the second main aim of this dissertation was to study the adult implications of female pubertal timing. In Papers III and IV, we examined long term implications of pubertal timing, particularly as it relates to somatic development. The findings suggested that pubertal timing does have future implications for women’s body perception and composition, with early developing females having higher body mass indexes in adulthood, but only under certain circumstances. The findings of this dissertation help further understanding of the soma et psyche implications of female pubertal timing. They indicate that pubertal timing has concurrent and future implications. It seems, however, that timing is not everything. The developmental significance of female pubertal timing appears to be very different under different contextual conditions. Thus, it is only when girls’ psychological and social contexts are considered that fruitful predictions can be made. As such, the findings have important implications for prevention, policy, and practice.</p>

The timing of pubertal development has important mental and physical health consequences. Individuals who enter puberty off-time are at greater risk for psychological disorders, social difficulties, and physical morbidity. One variable associated with early pubertal development is marital conflict. Life History Theory proposes that marital conflict signals an unreliable environment and promotes advanced pubertal timing to enhance reproductive fitness. Such calibrations allow individuals to unconsciously invest more resources in reproduction, following a quantity over quality approach. Despite research supporting the role of marital conflict in early-onset puberty, research has struggled to find a mechanism for this relationship. The current study examined two possible mediators: emotional insecurity and cortisol levels in a sample of children aged 6-12 years from 2-parent families. Neither variable was supported as a mediator of this relationship. However, parental depression significantly predicted pubertal development for girls. Findings regarding the role of parental depression in the timing of girl’s puberty support life history theory.

Orientador: Tamara Beres Lederer Goldberg / Banca: Eliana Aguiar Petri Nahás / Banca: Lilia Freire Rodrigues de Souza-Li. / Resumo: A osteoporose é uma doença que desperta grande interesse nos órgãos de saúde pública pois, a partir dos 50 anos de idade, 30% das mulheres e 13% dos homens sofrerão algum tipo de fratura, dela resultante. Esta incidência tende a quadruplicar nos próximos 50 anos, em virtude do aumento da expectativa de vida. A incidência de fraturas osteoporóticas está intimamente relacionada a massa óssea do indivíduo, dependente tanto da velocidade de perda que ocorre durante a vida, quanto da quantidade de tecido ósseo presente ao final da puberdade e início da vida adulta. O melhor método para avaliar a densidade mineral óssea (DMO) de adolescentes é a densitometria óssea realizada pelo método de absorciometria por dupla emissão de Raios X (DXA). Sua técnica propicia uma análise altamente precisa, com baixa exposição à radiação, sendo adequada para avaliação da população pediátrica. A compreensão do processo de mineralização óssea que ocorre na infância e adolescência permite o desenvolvimento de estratégias para a prevenção precoce da osteoporose. Se o ganho de massa óssea puder ser otimizado durante a puberdade, é provável que os adultos e os idosos estejam menos susceptíveis às complicações da osteoporose. Avaliar a densidade mineral óssea de adolescentes do sexo feminino, observando seus valores para cada uma das faixas etárias e determinar o comportamento da DMO dessas adolescentes, em função da faixa etária, da maturação esquelética e dos caracteres sexuais secundários, avaliados pelo desenvolvimento mamário. 58 adolescentes saudáveis, do sexo feminino, na faixa etária de 9 a 20 anos incompletos, residentes no município de Botucatu-SP, foram avaliadas quanto a ingestão de cálcio, peso, estatura, índice de massa corpórea (IMC), estágio puberal de mamas, maturação esquelética e densidade mineral óssea. A massa... (resumo completo, clicar acesso eletrônico abaixo) / Abstract: Osteoporosis is a disease that attracts great interest from public health agencies, since, as from their fifties, 30% of women and 13% of men will suffer some type of fracture resulting from it. Such incidence tends to become fourfold in the next 50 years due to the increase in life expectancy. The incidence of osteoporotic fractures is closely related to the individual's bone mass, depending on both the speed of loss, which occurs during one's lifetime, and the amount of bone tissue existing in late puberty and early adulthood. The best method to evaluate bone mineral density (BMD) in adolescents is bone densitometry performed by dual energy X-ray absorptiometry (DEXA), as its technique provides a highly accurate analysis, with low exposure to radiation. It is also adequate for evaluating the pediatric population. Understanding the bone mineralization process that occurs in childhood and adolescence enables the development of strategies for early osteoporosis prevention. If bone mass gain can be optimized in puberty, it is likely that adults and older persons will be less susceptible to complications stemming from osteoporosis. To evaluate BMD in female adolescents by observing its values for each age range and to determine the behavior of such adolescents' BMD, in function of their age range, as well as of their skeletal maturity and secondary sexual characteristics as evaluated by breast development. Fifty-eight healthy female adolescents aged 9 to 20 incomplete years and residing in the city of Botucatu-SP were evaluated as regards calcium intake, weight, height, body mass index (BMI), pubertal stage of breasts, skeletal maturity and BMD. Body mass was measured by means of bone densitometry (DEXA) performed in the lumbar regions of the spine, proximal femur and total body. Calcium intake was estimated by a non-consecutive three-day food record... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:29:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-09-02Bitstream added on 2014-06-13T20:20:23Z : No. of bitstreams: 1 oliveira_mrm_me_botfm.pdf: 215081 bytes, checksum: 2a596ef7138e12621ed26e380288c486 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A osteoporose é uma doença que desperta grande interesse nos órgãos de saúde pública pois, a partir dos 50 anos de idade, 30% das mulheres e 13% dos homens sofrerão algum tipo de fratura, dela resultante. Esta incidência tende a quadruplicar nos próximos 50 anos, em virtude do aumento da expectativa de vida. A incidência de fraturas osteoporóticas está intimamente relacionada a massa óssea do indivíduo, dependente tanto da velocidade de perda que ocorre durante a vida, quanto da quantidade de tecido ósseo presente ao final da puberdade e início da vida adulta. O melhor método para avaliar a densidade mineral óssea (DMO) de adolescentes é a densitometria óssea realizada pelo método de absorciometria por dupla emissão de Raios X (DXA). Sua técnica propicia uma análise altamente precisa, com baixa exposição à radiação, sendo adequada para avaliação da população pediátrica. A compreensão do processo de mineralização óssea que ocorre na infância e adolescência permite o desenvolvimento de estratégias para a prevenção precoce da osteoporose. Se o ganho de massa óssea puder ser otimizado durante a puberdade, é provável que os adultos e os idosos estejam menos susceptíveis às complicações da osteoporose. Avaliar a densidade mineral óssea de adolescentes do sexo feminino, observando seus valores para cada uma das faixas etárias e determinar o comportamento da DMO dessas adolescentes, em função da faixa etária, da maturação esquelética e dos caracteres sexuais secundários, avaliados pelo desenvolvimento mamário. 58 adolescentes saudáveis, do sexo feminino, na faixa etária de 9 a 20 anos incompletos, residentes no município de Botucatu-SP, foram avaliadas quanto a ingestão de cálcio, peso, estatura, índice de massa corpórea (IMC), estágio puberal de mamas, maturação esquelética e densidade mineral óssea. A massa... / Osteoporosis is a disease that attracts great interest from public health agencies, since, as from their fifties, 30% of women and 13% of men will suffer some type of fracture resulting from it. Such incidence tends to become fourfold in the next 50 years due to the increase in life expectancy. The incidence of osteoporotic fractures is closely related to the individual’s bone mass, depending on both the speed of loss, which occurs during one’s lifetime, and the amount of bone tissue existing in late puberty and early adulthood. The best method to evaluate bone mineral density (BMD) in adolescents is bone densitometry performed by dual energy X-ray absorptiometry (DEXA), as its technique provides a highly accurate analysis, with low exposure to radiation. It is also adequate for evaluating the pediatric population. Understanding the bone mineralization process that occurs in childhood and adolescence enables the development of strategies for early osteoporosis prevention. If bone mass gain can be optimized in puberty, it is likely that adults and older persons will be less susceptible to complications stemming from osteoporosis. To evaluate BMD in female adolescents by observing its values for each age range and to determine the behavior of such adolescents’ BMD, in function of their age range, as well as of their skeletal maturity and secondary sexual characteristics as evaluated by breast development. Fifty-eight healthy female adolescents aged 9 to 20 incomplete years and residing in the city of Botucatu-SP were evaluated as regards calcium intake, weight, height, body mass index (BMI), pubertal stage of breasts, skeletal maturity and BMD. Body mass was measured by means of bone densitometry (DEXA) performed in the lumbar regions of the spine, proximal femur and total body. Calcium intake was estimated by a non-consecutive three-day food record... (Complete abstract click electronic access below)

Adolescent sexual intercourse can be viewed as a normal developmental experience, but intercourse also is linked to unplanned pregnancies, Sexually Transmitted Diseases (STDs). and Acquired Immune Deficiency Syndrome (AIDS). Consequently, there continues to be a high level of scientific interest in understanding antecedents of adolescent sexual behavior, especially early and more risky sexual intercourse. This study examined several key antecedents of adolescent sexual intentions and behavior, including pubertal development (pubertal status, change over time, and pubertal timing). parent/teen communication, and teen sexual values. Analyses were based on longitudinal data collected in 1991, 1992, and 1993 from parents and teens during the FACTS & feelings project conducted within three areas in northern Utah. Regression and path analyses were used to test the direct and indirect effects among the variables. Parent/teen communication quality had a significant positive effect on teen sexual abstinent values for both males and females. Sexual abstinent values had a strong negative effect on sexual intentions for both males and females. Sexual values were more strongly related to sexual behavior for females than for males. Sexual intentions had a significant effect on sexual behaviors for both males and females, although this effect was stronger for males than for females. Pubertal timing had a significant effect on behaviors for males and a smaller although significant effect for females Age also had a significant positive effect for both male and female adolescents. Overall, within these analyses, females were more influenced by values which directly and indirectly affect sexual behaviors. Males were more influenced by the FACTS & feelings treatment, pubertal timing, and sexual intentions.

To date, no prior research has examined the combined roles of childhood family adversity and pubertal timing in longitudinal pathways to depressive symptomatology in adulthood. The present study was conducted with 225 men and 225 women to explore the unique and combined roles of childhood family adversity and pubertal timing on depressive symptoms in a community sample of married adults. Results for both men and women indicated significant main effects of a cumulatively risky family environment on depressive symptoms, as well as main effects of families with higher levels of abuse and neglect, chaos and disorganization, and interpersonal family conflict. A significant moderating relation was found for women with earlier pubertal timing and higher levels of childhood interpersonal family conflict on greater levels of depressive symptoms in adulthood. No other significant relations were determined in other moderation and mediational analyses. This project furthers our understanding of how the combined roles of pubertal timing and childhood family experiences can clarify the developmental, evolutionary, and clinical theories that link childhood and adolescent experiences to depression in adulthood. Specifically, childhood home environments defined by frequent interpersonal conflict (quarreling, arguing, and shouting), combined with early pubertal development, may play an important role in predicating depressive symptomatology among adult women.

<p>This thesis tested and extended the peer socialization hypothesis, a psychosocial model that identifies the interpersonal and contextual conditions in which pubertal development is linked to delinquent behavior such as alcohol use. Although there is support for the hypothesis in early empirical work, particularly for female adolescents, more recent work has shown mixed results. Furthermore, there are gaps within the peer socialization hypothesis: a) the theory does not discuss if the mediation process pertains to male adolescents, b) it does not address the role of pubertal tempo, and c) it implies, but does not explicitly model, a role for tempo with regards to including other-sex friendships into the friend group. Using the Internet Surveys About You (iSAY) study (<em>n</em>=1020), the peer socialization hypothesis and proposed extensions were tested separately by sex. Female adolescents initiated inclusion of other-sex friends into the friend group earlier than male adolescents. However, there were no observed sex differences in the tempo of other-sex friendships. Female adolescents’ pubertal development was not related to their other-sex friendship development nor was pubertal development and other-sex friendship development related to their alcohol use. Male adolescents’ pubertal timing was associated with the timing of other-sex friendship uptake in that later maturing adolescents displayed earlier initiation of other-sex friendships. Male adolescents’ other-sex friendship development was not related to their alcohol use. Implications of this work are that other-sex friendships may no longer be a context of increased risk for alcohol use for early maturing adolescents and interventions targeting this social context may not be as effective. </p>

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Social media engagement has become a critical part of adolescent social interactions, making it important to examine individual differences in motivations for social media engagement as well as associated adjustment outcomes. Additionally, much of the extant research focuses on how much time adolescents spend on social media; researchers have only recently begun to differentiate specific social media behaviors and their varied role in adolescent development (e.g., Valkenberg & Peter, 2011). Based on recent research, I investigated four social media behaviors: self-disclosure, self-presentation, lurking, and social monitoring, along with social media engagement in terms of time and frequency. Based on hormonal activation theory (Forbes & Dahl, 2010), I focused on pubertal and social goal correlates of individual differences in social media engagement among adolescents. I also examined positive (prosocial support) and negative (peer victimization, internalizing problems) adjustment associated with social media engagement. Participants were 426 public school students (54.2% female, 73.6% Caucasian, mean age = 12.91, SD = .92) from sixth (N = 152), seventh (N = 142), and eighth (N = 132) grades who completed self-reported survey measures during their Health classes. Adolescents used more passive (lurking, social monitoring) than active social media (self-disclosure, self-presentation) behaviors. Girls reported more social media engagement than boys, and older adolescents reported more social media engagement than younger adolescents. Pubertal timing was not associated with social media engagement; instead, social goals (i.e., popularity goals and preference goals) were strongly associated with adolescents’ social media use. Social media engagement was reliably associated with adolescent adjustment. Self-presentation may function as a double-edged sword, promoting peer prosocial support but also increasing the risk for peer victimization and internalizing problems. Self-disclosure was uniquely associated with an increased risk of peer victimization, and lurking was uniquely associated with internalizing problems. Social monitoring was not uniquely associated with any of the adjustment outcomes. Contrary to previous literature (e.g., Kross et al., 2013), the amount of time spent on social media was not uniquely associated with any adjustment outcomes after social media behaviors were controlled, suggesting the importance of examining what adolescents are doing with that time. Unexpectedly, the frequency of social media use (a measure less often considered in the literature) appeared to be uniquely associated with more adaptive adjustment. The association between social media engagement and adjustment was stronger for girls than for boys (particularly for peer victimization). Findings extend previous research demonstrating the importance of considering specific social media behaviors in adolescent development. Future research should longitudinally examine the role of social media engagement on adolescent adjustment. Additionally, multi-method approaches (e.g., observational data collection, peer nominations) should be utilized to better understand the role of social media engagement on adolescent development. Finally, future research should examine different social media platforms (e.g., Twitter, Fortnite, Snapchat) and adolescent adjustment. / Psychology