Puberty and Adolescence Among Bangladeshi and British Youth
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Durham E-Theses Juvenility, Puberty and Adolescence Among Bangladeshi and British Youth HOUGHTON, LAUREN,CLAIRE How to cite: HOUGHTON, LAUREN,CLAIRE (2013) Juvenility, Puberty and Adolescence Among Bangladeshi and British Youth, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/6958/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk 2 JUVENILITY, PUBERTY AND ADOLESCENCE AMONG BANGLADESHI AND BRITISH YOUTH LAUREN C. HOUGHTON MATERIAL ABSTRACT The ABBY (Adolescence among Bangladeshi and British Youth) Project explores the relationship between migration and growing up from a biocultural perspective. Based on evolutionary hypotheses, it tests for facultative adaptation to different developmental environments during the transition from child to adolescent using contrasting conditions within ethnicity, ecology, and migration. I explore the relationship between these variables and the timing and tempo of adrenarche, thelarche, pubarche and menarche through comparisons of biological and cultural markers of development among 488 girls, aged 5–16, belonging to the following groups: Sylheti, first generation British-Bangladeshi, second generation British-Bangladeshi and white British. This project supports evidence that the timing, tempo and experience of juvenile and pubertal development vary across populations with possible lasting implications for the strategic allocation of reproductive effort. Specifically, adrenarche occurred two years earlier in first generation migrant girls to Britain, suggesting that change in ecological factors results in more rapid juvenile onset. Thelarche occurred earlier with increasing individual and ancestral generations lived in the UK, suggesting that local ecological factors result in earlier pubertal onset. Contrary to predictions, menarcheal timing and oestrogen levels did not differ significantly among groups. Acculturation did not account for differences in behaviours during juvenile and pubertal development between groups. Instead, the stages of practising to being dedicated to hijab (which occur during juvenility and after puberty, respectively) better reflect the social process of growing-up as Bangladeshi girls in East London. Growing up here may be uniquely stressful among first generation migrants. Psychosocial stress may interact with other ecological factors resulting in an overall slower tempo of juvenile development. The extended period of plasticity during juvenility among girls who experienced a change in socio-ecological factors may be an adaptive response to ensure a better tracking of current socio-ecological conditions and also a better prediction of later ones. 2 JUVENILITY, PUBERTY AND ADOLESCENCE AMONG BANGLADESHI AND BRITISH YOUTH Lauren Claire Houghton Thesis submitted for the degree of Doctor of Philosophy to Department of Anthropology Durham University 2013 3 4 TABLE OF CONTENTS Material Abstract ..................................................................................................................... 1 Table of Contents ..................................................................................................................... 5 List of Figures ........................................................................................................................... 9 List of Tables .......................................................................................................................... 10 List of Photos .......................................................................................................................... 10 List of Abbreviations and Terms .......................................................................................... 11 Declaration.............................................................................................................................. 13 Statement of Copyright ......................................................................................................... 13 Acknowledgements ................................................................................................................ 14 PREFACE ............................................................................................................................... 16 CHAPTER 1: INTRODUCTION AND BACKGROUND ................................................. 20 Summary ................................................................................................................................. 20 Juvenility, Evolution and the Human Life Course ............................................................. 21 Theories of Identity Development ....................................................................................... 25 Adolescence and Ethnic Identity ......................................................................................... 26 Life History Theory Applied to Juvenility........................................................................... 27 The Juvenile Period, Ethnicity and Ecology ....................................................................... 29 Adrenarche ........................................................................................................................... 29 Markers of Adrenarche .................................................................................................... 32 Timing of Adrenarche ...................................................................................................... 34 Ethnic and Ecological Variation in Adrenarche .............................................................. 34 Physiological and Psychosocial Mediators of Adrenarche .............................................. 35 Puberty ................................................................................................................................. 37 Markers of Puberty .......................................................................................................... 38 Oestrogenic Markers of Puberty ...................................................................................... 41 Timing of Puberty: Chronology, Order and Tempo ........................................................ 42 The Relationship Between Adrenarche and Puberty ........................................................... 49 Juvenility in a Biocultural Migrant Study ........................................................................... 52 Rationale behind Study predictions ..................................................................................... 56 Study Design and Hypotheses ............................................................................................... 59 INTERLUDE A ...................................................................................................................... 63 CHAPTER 2: STUDY POPULATION AND METHODS ................................................ 64 Summary ................................................................................................................................. 64 Introduction: Biocultural, Mixed Methods Research........................................................ 65 Study Design ........................................................................................................................... 67 Participant Classification ...................................................................................................... 68 Study Setting: London, UK and Sylhet Town, Bangladesh ............................................... 71 ABBY Project Phases ............................................................................................................ 75 Phase 1: Pilot........................................................................................................................ 76 Field Testing .................................................................................................................... 76 Laboratory Testing of Salivary DHEAS and Urinary Oestrogens................................... 79 Phase 2: Recruitment ........................................................................................................... 81 Sampling Technique ........................................................................................................ 81 School Recruitment .......................................................................................................... 81 5 Participant Recruitment ................................................................................................... 85 Informational Sheets, Parental Consent and Child’s Assent ........................................... 85 Mock of Collection Materials .......................................................................................... 87 Icebreaker Activity..........................................................................................................