Adolescence Physical and Cognitive Development

• Puberty


  The time in life when a boy or girl becomes sexually mature, usually between ages 10-14 for girls and 12-16 for boys, causing physical changes that affect boys and girls differently
• Signs of Physical Maturation

  • Bodily changes including increase in height, weight, fat and muscle content
  • Sexual maturation including changes in reproductive organs and secondary sex characteristics
• Physical Growth


  1. Girls start growth spurt around age 11, reach peak around 12, mature by 15

  2. Boys start growth spurt around 13, reach peak around 14, mature by 17

  3. Bones become longer and denser

  4. Muscle fibers become thicker and denser, more pronounced in boys

  5. Body fat increases more rapidly in girls

  6. Heart and lung capacity increase more in boys
• Sexual Maturation


  1. Girls: Breast growth, pubic hair, menstruation (menarche) around 13

  2. Boys: Testes/scrotum growth, pubic hair, first ejaculation (spermarche) around 13
• Mechanisms of Maturation


  • Pituitary signals adrenal glands to release androgens, initiating body hair
  • Pituitary signals ovaries to release estrogen, causing breast/genitalia development and fat accumulation in girls
  • Pituitary signals testes to release testosterone, causing male genitalia development and muscle mass increase in boys
  • Estrogen and androgen present in both sexes, just in different amounts
• Timing of puberty is influenced 50-75% by genetics, with earlier puberty in well-nourished, healthy adolescents
• Social environment influence on puberty

  Earlier menarche in girls experiencing chronic stress/lack of supportive parents, may be evolutionary adaptation to reproduce earlier
• Paternal investment theory


  Frequent, positive father interactions delay puberty in girls, infrequent/negative interactions accelerate it
• Psychological Impact of Puberty

  • Girls more worried about appearance, dissatisfied with looks
  • Boys unhappy when they don't meet muscular ideal
  • Moodiness not primarily due to hormones
• Rate of Maturation


  • Early maturation harmful for girls, can be offset by supportive parents
  • Timing of maturation stressful for boys, but puberty itself may be stressful regardless of timing
• Nutrition


  • Teenage girls need ~2200 calories, boys ~2700 calories per day
  • Need calcium for bone growth, iron for hemoglobin
  • Often consume too much fast food, lacking balanced nutrition
• Obesity


  • Overweight youth often unpopular, low self-esteem, at risk for health issues
  • Heredity plays major role, influencing activity levels and metabolism
  • Effective weight loss programs focus on changing eating, activity, and sedentary habits
• Anorexia Nervosa


  Persistent restriction of energy intake, intense fear of weight gain, disturbance in self-perceived weight/shape
• Bulimia Nervosa


  Recurrent episodes of binge eating followed by compensatory behaviors to prevent weight gain
• Anorexia Nervosa


  Persistent energy intake restriction; intense fear of gaining weight or of becoming fat, or persistent behavior that interferes with weight gain; and a disturbance in self-perceived weight or shape
• Anorexia Nervosa


  The individual maintains a body weight that is below a minimally normal level for age, sex, developmental trajectory, and physical health
• Anorexia Nervosa


  Individuals with this disorder typically display an intense fear of gaining weight or becoming fat
• Anorexia Nervosa


  The experience and significance of body weight and shape are distorted in this individual. Some individuals feel globally overweight. They may employ a variety of techniques to evaluate their size or weight including frequent weighing, obsessive measuring of body parts, and persistent use of a mirror to check for perceived areas of "fat"
• Bulimia Nervosa


  An "episode of binge eating" is defined as eating, in a discrete period of time (2 hours), an amount of food that is definitely larger than most individuals would eat in a similar period of time under similar circumstances
• Bulimia Nervosa


  Occurrence of excessive food consumption must be accompanied by a sense of lack of control to be considered a binge eating
• Bulimia Nervosa


  The recurrent use of inappropriate compensatory behaviors to prevent weight gain, collectively referred to as purge behaviors or purging
• Bulimia Nervosa


  Individuals with bulimia nervosa place an excessive emphasis on body shape or weight in their self-evaluation, and these factors are typically extremely important in determining self-esteem
• Unfortunately, the cause of anorexia nervosa remains unknown. Like most eating disorders, it's a combination of low self-esteem, poor self-image, and other factors like biology and the environment. Peer pressure and unrealistic expectations of someone's body all play a role.
• Regular physical activity


  Exercising for 30 minutes, at least three times a week, at a pace that keep an adolescent's heart rate at about 140 beats per minute
• Benefits of participating in sports

  • Improved physical fitness
  • Enhanced self-esteem
  • Learning initiative
  • Learning teamwork
  • Learning competitiveness
• Approximately 5 to 10% of high school boys and 1 to 2.5% of high-school girls report having used anabolic steroids
• Anabolic steroids


  Drugs that are chemically similar to the male hormone testosterone, used to increase muscle size and strength and to promote more rapid recovery from injury
• Dangers of anabolic steroids

  • Damage to the liver, reproductive system, skeleton, and cardiovascular system (increasing blood pressure and cholesterol levels)
  • Mood swings, aggression, and depression
• Many adolescent deaths are due to accidents involving motor vehicles or firearms, and are often linked to driving too fast, drinking alcohol, and not wearing seat belts, as well as easy access to firearms in the home
• Adolescent risk-taking


  Adolescents take unnecessary risks while riding skateboards, scooters, or bicycles, drive cars recklessly, engage in unprotected sex, and sometimes use illegal and dangerous drugs
• Illusion of invulnerability


  Adolescents exaggerate the overall dangers of risky behaviors but believe they are much less likely than their peers to experience the harmful consequences
• Adolescents find the rewards associated with risky behavior far more appealing than adults do, so they are willing to ignore the risks
• Adolescent information processing


  • Acquire adultlike levels of knowledge and understanding in many domains
  • Become much better skilled at identifying strategies appropriate for a specific task, then monitoring the chosen strategy to verify that it is working
  • More likely to outline and highlight information, make lists of material they don't know well, and embed these activities in a master study plan
• Adolescent problem solving and reasoning

  • Solve problems more readily than children, using more sophisticated approaches like determining an answer mathematically or logically
  • Better skilled at finding weaknesses in arguments
• Adolescents may not always use their reasoning skills effectively, sometimes resorting to heuristics or dismissing evidence that is inconsistent with their beliefs
• Kohlberg's theory of moral development

  • Preconventional morality: Moral reasoning based on external forces like rewards and punishments
  • Conventional morality: Moral reasoning based on acceptance of social rules and internalization of moral standards
  • Postconventional morality: Moral reasoning based on abstract principles of morality
• Promoting moral reasoning


  • Exposure to more advanced moral reasoning
  • Involvement in religion and religious communities