Lecture 12: Physical and Cognitive Development in Adolescence

Five Developmental Universal Tasks of Adolescence

1. Accept full-grown body and changes of puberty

2. Acquire adult ways of thinking

3. Develop more mature ways of relating to peers of both sexes

Less rigidity of gender segregation

4. Consolidate an identity

5. Attain greater independence from the family

Puberty

The set of biological processes that change the immature child into a sexually mature person

• A gradual process of related events over a series of years, not a single event

• Timing

  Girls: 10-15

  Boys: 11.5-17

  Occurs earlier now could be due to improved health care & diets

• Growth patterns

  Youth progress through events at different rates, but all generally follow the same sequence

  - by uneven growth (asynchrony)

Two types of physical changes

• Overall Body growth

• Sexual Maturation

Overall Body growth

• Controlled by increases in growth hormones such as thyroxine

• Growth - First outward sign of puberty, a LARGE increase in size, strength, weight (gains around 50-75 lbs)

• Girls start spurt earlier (10 y.o.) last about 2.5 years

• Boys start spurt later (12.5 y.o.) and grow for a longer period of time

• Reverse of cephalocaudal trend the feet, legs, and hands grow first instead of other parts of the body

• i.e. lanky legs and clown feet seem disproportionate compared to the rest of the body

• Increase in appetite

• Increase in size + activity of oil-producing glands (acne breakouts) + new sweat glands (Stronger BO)

• See changes in muscle-fat ratio

• Girls add more fat than boys

• Boys will get more muscle strength than girls

Sexual maturation

1. Primary sexual characteristics 

• Involved reproductive organs directly  

• Ovaries, genitalia 

2. Secondary sexual characteristics 

• External physical changes that help distinguish human M + F in appearance 

• Breast development (females) + facial hair (males)  

• Both will have pubes  

General changes of sexual maturation

• Girls AND boys will have increased levels of androgens AND estrogens, level determined are sex-specific

• Boys get more androgens

testosterone -> muscle growth in body size, sex characteristics

• Girls get more estrogen

Cause breasts and uterus to mature, and fat to accumulate that regulates the menstrual cycle

• Menarche (First menstruation) – Occurs late in the sequence, typically around 12.5 y.o.

• When stored sufficient body fat (typically around 100 lbs)

Factors Affecting Timing of Puberty

Timing is influenced by both genes and environment. 

• Approximately 2/3 of variation in age of puberty is genetic  

• See roles of genes via twin studies  

  Identical twins hit puberty around a 2-months diff.  

  Fraternal – 12-months diff.  

Multiple aspects of the environment affect pubertal timing

Nutrition, weight, dieting, exercise  

• Girls need to reach a certain weight/fat accumulation  

• High lvls of exercise could delay it (chn in sports), bad diet and nutrition 

  There’s also psychosocial aspects that contribute: 

• Links between earlier pubertal timing + environmental stress: divorce, family conflict, father absences  

• Why might socioemotional stress matter?  

  Evolutionary model:  

  Argues humans have evolved to the emotional quality of their childhood environment,  

  In a stressful home environment, adaptive to mature early to leave + reproduce early   

Psychological Response to Pubertal Timing

• Early: Boys tend to fare better than girls  

  Early boys – Higher athleticism; Closer to the cultural ideal of men, ideal for boys to have a more muscular type of body compared to skinny body 

  Early girls – Mover further from thin ideal; Vulnerable to sexual harassment; Already developed breasts than the rest of classmates 

• Late Bloomer: Girls fare better than boys  

Body Image is a Focal concern

A strong predictor for self-esteem

• Amazing amount of growth 

• Adolescents are now aware of changing bodies (Compared to growth during infancy)  

• Adolescents as a marginal group – A group between cultures, within-group conformity is vital  

• Mass media contribute by presenting one-dimensional images of attractiveness based on gender: 

  Girls: Curvy, thin, sexy, attractive face 

  Boys: Lean, muscular, attractive face  

Eating disorders 

• Girls: Increased risk of eating disorders, such as anorexia (Peak around around 10-15 y.o)  

 

Body Image Among Boys  

• Primary concerns: Height, muscle, physical strength: At risk of steroid abuse  

• i.e. Boys talking abt body image  

Body Image: Other Contributing Factors

• Multiple factors lead teens to internalize these narrow cultural ideals  

• Jones et al. (2004) tested factors among 780 7^th-10^th graders  

• In research, peer appearance conversations mattered the most 

• All the factors of BMI, appearance magazine exposure + conversations with friends, peer appearance criticism are all caused by the internalization of media that leads to body image dissatisfaction  

General Advances in Logical Thinking – Shift to Formal Operational Thinking

• Emerged from 11-15 y.o. 

• Can now deal with the abstract and hypothetical thought  

• Thinking is more enlightened, imaginative, idealistic, and rational  

• Piaget believed in this stage; reason is like a scientist (using logical = highest lvl of reasoning)  

Critique:  

• Research shows the growth of formal reasoning abilities is slower and less complete than Piaget believed  

• Adults still perform poorly with deductive reasoning some college students even fail at tests for formal operational thinking   

 

Three Advances in Adolescent Thinking 

1. Thinking about possibilities (“what if”) – propositional thought 

• Able to evaluate logic of propositions without referring to real-world circumstances 

• Can better handle abstract + hypothetical thinking  

• Allows adolescents to fantasize and speculate on a grander scale (the person you are in the moment is one aspect of many things) 

• “What ifs”  

• Able to consider range of alternatives in problem solving  

 

2. Thinking through hypotheses (“If, then”) -  

• Hypothetico deductive reasoning 

• Able to formulate, test, and evaluate hypotheses in an orderly fashion  

• i.e. What makes the pendulum swing faster?  

• Young chn randomly solve probs. 

• Adolescents do it more systematically (Finding variables and testing hypothesis with purpose)  

• Teens may see weight, string length, AND force play a factor in the pendulum swing

   

3. Thinking about abstract concepts (i.e. love, faith, greed) 

• Advances lead them to critically examine assumptions 

• i.e. politics 

Role of Brain Development

• Improvement in rational thinking fostered by extensive maturation of prefrontal cortex, gradual growth  

  Maturation takes place in important areas for planning, thinking ahead, weighing risks + rewards  

• Includes synaptic pruning, myelination, increased connectivity in PREFRONTAL CORTEX connections to other brain parts 

• But adolescents still do not fully resemble adults in their decision-making  

• See risk-taking and “What were they thinking?" moments – Why?  

  I.e. texting and eating while driving 

• Decision-making in the real world is the product of both logical reasoning and psychosocial factors (i.e. impulse control + handling peer pressure) – These two components mature at different rates 

What does psychosocial immaturity stem from?

• From a gap in the maturation of brain networks  

• Socioemotional networks develop early – Highlights emotion, reward, sensation-seeking, positive interactions  

• Cognitive control systems develop later and more gradually; Responsible for  

  Impulse control  

  Emotional regulation   

  Delay of gratification  

  Resistance to peer influence  

  Weigh risk + reward differently than adults  

• i.e. Push back: Too much focus on negative stereotypes?  

  Argued not ALL risk-taking is negative 

  i.e. trying a challenging sport or applying for something that is competitive  

  Cannot succeed with developmental tasks if take no risks 

“Side effects” of new thinking abilities

1. See intense pre-occupation with the self and with presenting the self in the best light  

• i.e. what other people think of them  

2. Two distortions in the relation between self and others 

• imaginary audience i.e. walking alone to the bus stop and think everyone is watching

• specialness - personal fable

3.  Sensitive to hypocrisy – Often leads to argumentativeness  

4.  Difficulty with everyday decision-making  

imaginary audience

Erroneous belief that one’s behavior is the subject of constant public attention

personal fable

Erroneous belief that one’s thoughts, feelings, and experiences are totally unique