Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. C H A P T E R Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 3 Puberty, Health, and Biological Foundations “In youth, we clothe ourselves with rainbows and go brave as the zodiac.” — Ralph Waldo Emerson American Poet and Essayist, 19th Century “In youth, we clothe ourselves with rainbows and go brave as the zodiac.” — Ralph Waldo Emerson American Poet and Essayist, 19th Century

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 2 Puberty The period of rapid physical maturation involving hormonal and bodily changes that take place primarily in early adolescence

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 3 Hormones Powerful chemicals secreted by the endocrine glands; carried through the body by the bloodstream. Androgens: The main class of male sex hormones Estrogens: The main class of female sex hormones

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 4 Hormones Hormone Levels by Sex and Pubertal Stage for Testosterone and Estradiol Fig. 3.1

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 5 The Endocrine System Hypothalamus –Structure in the brain –Secretes releasing factor Pituitary Gland –Regulates other glands –Secretes FSH and LH Gonads –Testes, ovaries –Secretes sex hormones

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 6 The Endocrine System The Major Endocrine Glands Involved in Pubertal Change Fig. 3.2

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 7 Feedback System of Sex Hormones LH-RF (lutenizing hormone-releasing factor) and FSH-RF (follicle stimulating hormone-releasing factor) stimulate pituitary gland LH (lutenizing) and FSH (follicle stimulating) stimulate gonads (Testes in males, ovaries in females) Fig. 3.3

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 8 Adrenarche Involves hormonal changes in the adrenal glands, from about 6-9 years of age –Gonadarche: What most people think of as puberty; involving sexual maturation and development of reproductive maturity –Spermarche: A boy’s first ejaculation of semen –Menarche: A girl’s first menstrual period

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 9 Growth Spurt Occurs 2 years earlier for girls (age 11.5) than boys (13.5) on average Girl increase 3.5 inches per year, boys about 4, during this period Weight gain follows roughly same timetable as height gain Girls gain hip width while boys gain shoulder width

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 10 Growth Spurt Pubertal Growth Spurt Fig. 3.4

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 11 Sexual Maturation Males –Increase penis and testicle size –Pubic hair –Voice change –Spermarche –Armpit hair –Facial hair

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 12 Sexual Maturation Females –Breasts enlarge –Pubic hair –Armpit hair –Menarche

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 13 Sexual Maturation Fig. 3.5 Normal Range and Average Development of Sexual Characteristics in Males and Females

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 14 The Age at Menarche has Declined Median Ages at Menarche in Selected Northern European Countries and the United States from 1845 to 1969 Fig. 3.7

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 15 Psychological Dimensions of Puberty Body Image Hormones and Behavior Menarche and the Menstrual Cycle Early and Late Maturation Are Puberty’s Effects Exaggerated?

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 16 Pubertal Timing and Health Care Discussions with sensitive and knowledgeable healthcare providers and parents can improve the coping abilities of the off-time adolescent

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 17 The Neuron Fig. 3.9

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 18 The Brain’s Four Lobes Fig. 3.11

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 19 Experience and Plasticity Deprived and Enriched Environments Can New Brain Cells Be Generated in Adolescence? Can the Adolescent’s Brain Recover from Injury? Brain Development and Education

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 20 The Evolutionary Perspective Clip art copyright © Used with permission. Natural Selection and Adaptive Behavior Evolutionary Psychology –Emphasizes importance of adaptation, reproduction, and “survival of the fittest” in explaining behavior

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 21 Evolutionary Developmental Psychology Extended “juvenile” period to develop brain Childhood functions as preparation for adulthood Evolved psychological mechanisms are domain-specific Evolved behaviors not necessarily adaptive

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 22 Evaluating Evolutionary Psychology The Genetic Process –DNA Chromosomes Genes –Units of hereditary information

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 23 Evaluating Evolutionary Psychology Cells, Chromosomes, Genes, and DNA Fig. 3.15

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 24 Genotype and Phenotype Genotype: the actual genetic material Phenotype: expressed characteristics (the phenomenon that appears) Clip art copyright © Used with permission.

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 25 Heredity-Environment Interaction Behavior genetics: –The study of the degree and nature of behavior’s hereditary basis –Twin study –Adoption Study

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 26 Heredity-Environment Correlations Passive genotype-environment correlations –Occur when biological parents, who are genetically related to the child, provide a rearing environment for the child

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 27 Heredity-Environment Correlations Evocative genotype-environment correlations –Occur when the adolescent’s genotype elicits certain types of physical and social environments

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 28 Heredity-Environment Correlations Active (niche-picking) genotype- environment correlations –Occur when adolescents seek out environments they find compatible and stimulating

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 29 Exploring Heredity & Environment Shared environmental influences –Adolescents’ common experiences, such as their parents’ personalities, social class, and neighborhood

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 30 Exploring Heredity & Environment Nonshared environmental influences –The adolescent’s own unique experiences, both within a family and outside the family, that are not shared by a sibling

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 31 Heredity & Environment “The interaction of heredity and environment is so extensive that to ask which is more important, nature or nurture, is like asking which is more important to a rectangle, height or width.” --William Greenough, University of Illinois

Copyright © 2007 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill 32 Taking it to the Net For more information on material covered in this chapter, visit our Online Learning Center: