Heredity vs. Environment in Intelligence

1. Heredity vs. Environment in Intelligence ED PSYC 302

2. Intelligence • Intelligence is a concept that involves all types of cognitive processes • Traditionally cognitive psychologists have viewed intelligence as • Learning from experience and adapting to the environment • Understanding and controlling one’s own cognitive processes

3. Heredity vs. Environment • Nature vs. Nurture • Sir Francis Galton • Sir Francis Galton in the late 19th Century studied family histories and concluded that success & eminence ran in families over generations • Galton discounted the advantages of superior schooling and social advantages and proposed that eminence ran in families because intelligence was passed from generation to generation.

4. Sir Francis Galton • Galton published his findings in his 1869 book Hereditary Genius and is credited with coining the term nature vs. nurture. • Although Galton’s tests for intelligence were not successful he created an interest in intelligence that eventually set the stage for breakthroughs by subsequent investigators.

5. Heredity & Intelligence • Intelligence is clearly a family characteristic. • Heritability accounts for considerable amount of total variance in general cognitive ability. • Different cognitive abilities are influenced by same genetic factors

6. Heredity & Intelligence • Genetic research has made important discoveries during last few decades. • General cognitive ability = g • g runs in families • Adoption & twin studies -identical twins reared apart are almost as similar for g as identical twins reared together. -Galton’s twin studies in 1876- studied how similarity of twins changes over course of development -heritability increases from infancy to adulthood

7. Heredity vs. Environment • Both Environment & Heredity are important in the development of intelligence. • The “epigenetic” model proposes that an interaction of both environment and heredity is necessary for an individual to achieve their full potential. • However, Twin Studies do support the hypothesis that intelligence is a genetic characteristic

8. Identical twins tend to have more similar IQ scores than fraternal twins do. This is also true when identical twins are raised in different homes. Cognitive development of adoptive children more closely resembles that of their biological parents than their adoptive parents. Twin Studies

9. Heredity vs. Environment • Theorists believe it is ultimately impossible to separate the effects of heredity & environment. • Together, heredity & environment influence development & IQ in ways that will probably never be separated.

10. Environment & Intelligence • While nature may supply some parameters of intelligence, it is what we do within and around those parameters that makes a real difference to learners. • Relationships and activities a child has in his/her immediate environment is driving force behind effective human development.

11. Parenting styles Nutrition Exposure to illness Parental educational level Environmental crowding Security of attachment to caregiver Access to stimulating & enriching experiences Access to sources of knowledge Level of social support Noise level Schooling Stability of neighborhoods Non-genetic factors

12. Environment & Intelligence • Environment clearly has a big effect on IQ scores • Poor nutrition in early years of development leads to lower IQ scores. • Mother’s alcohol use during pregnancy leads to lower IQ scores. • Attending school positively effects IQ • Families and cultures in which children are raised have a significant impact on the cognitive abilities children acquire. Mental Age IQ = __________________ x 100 Chronological Age

13. Environment & Intelligence • Permanently changing a child’s environment from impoverished to enriched and stimulating can lead to increases in intelligence scores up to 20 to 25 points. • Slow but steady increase in the population’s IQ scores due to better -nutrition -schooling -stimulation (TV and Reading materials)

14. Racial / Ethnic Groups & Intelligences • Studies have shown considerable IQ differences between African American and Caucasian children. • Due to the environment -economic circumstances affecting quality of prenatal & postnatal nutrition -availability of stimulating books and toys -access to educational opportunities

15. Racial / Ethnic Groups & Intelligences • In recent years, African American and Caucasian children have become increasingly similar in IQ • Can be attributed to more equitable environmental conditions • Studies show that race has no basis in biology

16. Teaching/learning Process Implications • Do not over-rely on models that assume a nature orientation • Not nature vs. nurture but rather how the two work together • What is inherited can be changed • Race does not affect intelligence

17. Teaching/learning Process Implications • Learning how to Learn • Children are more receptive to learning when they feel wanted and valued and environment is meaningful, accepting, comfortable, orderly, and safe. • Active and learner centered • Connect with school’s social environment

18. Sources • Ormrod, J. E. (2000). Educational Psychology: Developing Learners (3rd ed.). Ohio: Merrill. • Dr. Thomas Shaffer, South Dakota State University. • Plomin, R. (1999). Genetics and intelligence. Journal of the American Academy of Child and Adolescent Psychiatry. 38(6), 786. • French, F. (2003). Revisiting Nature vs. Nurture: Implications for the Teaching/Learning Process. Education Canada. 43(2), 20-23.