PSYCH 250 1st Edition Lecture 13 Part 1Outline of Last Lecture I. New Challenges and Self - ConceptII. Children’s CultureIII. Peers and FriendshipA. AcceptanceB. BullyingIV. Family RelationshipsV. DivorceOutline of Current Lecture VI. Puberty and Physical ChangesVII. HormonesVIII. Physical GrowthIX. Sexual MaturationX. Body Rhythms XI. Difference in the Timing and Speed of PubertyXII. Sexual ActivityCurrent LectureAs children reach the age of adolescence, they all go through Puberty. Puberty is from a Latin word meaning “adult”, and is the period of life in which an individual becomes able to sexually reproduce. Puberty is universal among adolescents no matter the race or cultural differences, but is not universal in its timing, speed of occurrence, or impact on the individual’s psychosocial environment. Adolescents have already gone through an immensely different body change during their first years of life. However, puberty is different from the changes in infancy because the individual is actively aware of it.During adolescence there five major physiologic changes:1) Growth Spurt (directly related to the ability to reproduce)2) Development of Primary Sex Features3) Development of Secondary Sex Features4) Body Composition5) Changes to Circulation and RespirationsWhat exactly begins puberty? Puberty is a gradual process that begins at conception and continues into adolescence. The Hypothalamus sends a biochemical signal to the Pituitary Gland, which sends a sends a signal to the Gonads (testes in males and ovaries in females). The gonads then increase the production of sex hormones: estrogens and androgens (women produce more estrogens, and men produce more androgens). HormonesWhen puberty first begins, conflict, moodiness, and sexual urges do increase (especially during early puberty). However, the effect of hormones on these changes is often indirect and dependsheavily on the context of the individual’s psychosocial environment. A study done by Reed and Richards in 1998 suggests that the interactions of hormones and culture/emotional context may also play a part in trends of moodiness and conflict often observed in adolescents.High school and middle school students were asked to wear a pager throughout a given week. Each time they were paged, they had to write to down what they were doing, who they were with, and how they were feeling. Both groups had generally more negative moods than adults, but high schoolers tended correlate their negative moods with negative events.Physical ChangesThe growth spurt that occurs in adolescence is a rapid and sudden period of physical growth during puberty. On average, females tend to hit this growth spurt two years earlier than males (girls grow at about 10.5 years of age, and males at 12.5 years). This growth occurs in a sequence: weight, then height, and then muscle. During this growth spurt and throughout adolescence, individuals will gain 10-11 inches of heights and gain 50-75 lbs.However, this growth is not symmetrical. The first thing that begins growing is the head, followed by the hands and feet, the arms and legs, and finally the torso.In addition to this growth, body composition also changes. Females tend to gain more fat, and males tend to gain more muscle. As the lungs and heart increase in size and capacity, the individual develops at increased exercise tolerance.Sexual MaturationPrimary Sex Characteristics: these are parts of the body that are directly involved in sexual reproduction (testes and ovaries)Secondary Sex Characteristics: these are traits that are not necessary for reproduction (hair growth, deepening of the voice, body odor, breast development and acne).The sequence of puberty is also universal, but the timing and speed of it varies. Menarche: this is a girls first period and typically occurs between the ages of 10 ½ and 15, with the average age being 12 1/2. The menarche is a late marker that puberty has been occurring for quite some time.Spermache: typically occurs between the ages of 12 and 16 years, with the average age being 13.In the last 160 years, the age of the menarche has steadily declined. In 1840 the average age of menarche was 17 years, compared to the 12.5 years of today. This decline has been influenced by many factors including better nutrition, fortified foods, and change in lifestyles.Body Rhythms During adolescence the body’s natural time clock also seems to change. Most teenagers would rather stay up late, and sleep in late (phase – delay). Once teens have hit puberty the normal nighttime increase of the neurotransmitter melatonin (aids in falling asleep) begins 2 hours laterthan it did in early and middle childhood.However, this can lead to sleep deprivation if teenagers are not getting the right amount of sleep they need. Sleep deprivation puts teens at a high risk for:- Mood Disorders- Insomnia - Falling Asleep at the WheelA few high schools have experimented with later start and end times for their students, and have gotten many positive results such as fewer absences, higher G.P.A.s and a higher overall graduation rate.Difference in the Timing and Speed of PubertyThe timing and speed of puberty is determined by:Genes HormonesBody Fat StressHowever, research has shown that puberty may begin earlier for girls if there is a biologically unrelated male living in the home.Some adolescents may reach puberty earlier or later than their peers. This has negative and positive effects for both genders.Girls BoysEarly Maturers- Low self-confidence- Withdrawn- More deviant behavior- Low self-esteem- More long-term problems- MOST CONCERNED ABOUT- Popular- Confident- Positive self-image- More deviant behaviorLate Maturers- Popular- Socially inclined- Leaders- Positive self-image- Unpopular- Attention seeking- Negative self-image- Intellectual curiositySexual ActivitySex has become a normative thing of adolescents. Roughly 75% of teens have reported having sexual intercourse by 18-19 years of age, and a large minority of adolescents have reported being sexually active rather early (before age 15). Ethnicity and regional influences and differences have affected the age of onset of sexual activity. For example, the average age of first intercourse for African American males was 15 years, compared to 16.5 years for Hispanic Americans and White males and 17 years for Asian American males.The Prom Effect: The prom effect is a trend that shows