1. Parents & Peers

2. Early Stimulation Rats living in an enriched environment developed a heavier and thicker brain cortex Both nature and nurture sculpt our synapses Normal stimulation is critical Before puberty – pruning process After puberty- lose unused connections

3. Parents Parents do matter (seen most at the extremes) Family impacts most – political attitudes, religious beliefs, personal manners However, personality is shaped less by parents (less than 10% of differences between siblings is due to parents and environment)

4. Peers Peers have a lot of influence Teens who start smoking usually have friends who model smoking Children usually pick up the accent of their peers in the neighborhood (not their home)

5. A. Adolescence 1. Starts with sexual maturity and ends with social achievement of independent adult status. a. What happens in cultures where teens are self- supporting? Adolescence is shorter. 2. G. Stanley Hall (1904) – period of “storm and stress.” 3. Even though some people look back at adolescence in a negative way, for many people, they describe adolescence – in a positive manner.

6. B. Physical Development 1. Puberty – the time when one is maturing sexually a. Primary sex characteristics – reproductive organs and external genitalia b. Secondary sex characteristics – non-reproductive traits - breasts and hips in girls - deepened voice in boys - underarm hair in both sexes c. Girls - breasts develop around 10 - menarche – first menstrual period within a year of 12 d. Boys - first ejaculation about 14; usually a nocturnal emission

7. e. Like earlier life stages – sequence is more predictable then timing f. Early maturing - Boys – high self-esteem - girls – low self-esteem g. Brain - Cells stop increasing their connections -Pruning of unused connections - Frontal lobe lags behind the limbic system in development - This explains – impulsiveness, emotional storms, and risky behavior - The brain is different at the end of puberty