1. Unit 9 Developmental Psychology

2. Parents, Peers, and Early Experiences
Module 50
Learning Targets
50-1 Describe how early experiences can modify the brain.
50-2 Discuss the ways in which parents and peers shape children’s development.
Parents, Peers, and Early Experiences

3. How do early experiences modify the brain?
Mark Rosenzweig, David Krech, and their colleagues conducted research to question the impacts of early experiences on neural development in the brain. The researchers raised rats either alone in an environment without playthings, or with other rats in an environment much like a rat playground, enriched with playthings that changed daily.

4. What did the research show?
Rats in the impoverished environment, lacking company and playthings, saw impoverished brain growth as evidenced by brain weight and growth of synapses.

5. usually developed a heavier and thicker brain cortex.
What were the results?
The rats living in the enriched environment, which simulated a natural environment,
usually developed a heavier and thicker brain cortex.

6. What does the data indicate?
After 60 days in the enriched environment, the rats’ brain weights increased 7 to 10% and the number of synapses mushroomed by about 20%. (Kolb & Whishaw, 1998) The enriched environment literally increased brain power.

7. How does practice increase neural development?
String musicians who started playing before age 12 have larger and more complex neural circuits
controlling the note-making left-hand fingers
than do string musicians whose training started later.
(Elbert et al., 1995)

8. What are the applications of this research finding?
Such results have motivated improvements in environments for laboratory, farm, and zoo animals—and for children in institutions.
1980’s Romanian orphanage.

9. What Would You Answer?
Compared with rats raised in an enriched environment, which of the following is true of rats raised in isolation? A. Their brain cortex is less developed. B. Though neurologically similar, they fear other rats. C. Their brains have more connections. D. They have a thicker brain cortex. E. The differences between the two groups are not statistically significant.

10. Can touch and stimulation increase cognitive development?
Stimulation by touch or massage also
benefits infant rats and premature babies.
(Field et al., 2007; Sarro et al., 2014)
“Handled” infants of both species develop faster neurologically and gain weight more rapidly.
Preemies who have had skin-to-skin contact with their mothers sleep better, experience less stress, and
show better cognitive development 10 years later.
(Feldman et al., 2014)

11. How does experience change the brain?
Due to the brain’s amazing plasticity, neural tissue changes and reorganizes in response to new experiences. New neurons are also born. If a monkey pushes a lever with the same finger many times a day, brain tissue controlling that finger will change to reflect the experience.

12. How much blame or credit do parents deserve?

13. What does the research indicate?
Shared environmental influences from the womb
onward typically account for less than 10% of children’s differences.
In the words of behavior geneticists
Robert Plomin and Denise Daniels
“Two children in the same family are [apart from their shared genes] as different from one
another as are pairs of children selected randomly from the population.”
(1987; Plomin, 2011)

14. credit and blame Developmental
psychologist Sandra Scarr believes “parents should be given less credit for kids who turn out great and blamed less for kids who don’t.”

15. Cultural differences in parenting expectations.
Asian-Americans and European-Americans often differ in their parenting expectations.
An Asian-American
mother may push her children to do well, but usually not in a way that strains their relationship.
(Fu & Markus, 2014)
Amy Chua, law professor
and author of Battle Hymn of the Tiger Mother
(2011)

16. How do childhood peers (nurture) impact our behaviors?
Preschoolers who disdain a certain food often will eat that food if put at a table with a group of children who like it.
Children who hear English spoken with one accent at home and another in the neighborhood and at school will likely adopt the accent of their peers, not their parents.
Teens who start smoking typically have friends who model smoking, suggest its pleasures, and offer cigarettes.
(Rose et al., 1999; Rose et al., 2003)

17. peer power As we develop, we play, date, and partner with peers.
No wonder children and youths are
so sensitive and responsive to peer
influences.

18. How can parents influence the peer relationships?
The power to select a child’s neighborhood and schools gives some parents the ability to influence the culture that shapes the child’s peer group. Because neighborhood influences matter, parents may want to become involved in intervention programs that aim at a whole school or neighborhood.

19. Peers or parents?
To what extent, and in what ways, have your peers and your parents helped shape who you are? How have they influenced your taste in music or clothing? How have they impacted your potential career choice? Political or religious beliefs?
Talk about it.

20. Learning Target 50-1 Review
Describe how early experiences can modify the brain.
As a child’s brain develops, neural connections grow more numerous and complex. Experiences then trigger a pruning process, in which unused connections weaken and heavily used ones strengthen.
Early childhood is an important period for shaping the brain, but thanks to plasticity, the brain modifies itself throughout our lives in response to our learning.

21. Learning Target 50-2 Review
Discuss the ways in which parents and peers shape children’s development.
Family environment and parental expectations can affect children’s motivation and future success. Personality, however, is mostly not attributable to the effects of nurture.
As children attempt to fit in with their peers, they tend to adopt their culture—habits, accents, and slang, for example.
By choosing their children’s neighborhoods and schools, parents exert some influence over peer group culture.