BIO 500 Effects of Heredity and Environment on IQ Essay
BIO 500 Effects of Heredity and Environment on IQ Essay
Details:
Use Excel or SPSS to complete Exercise 1 in the Cumulative Review Exercises on page 485 in the textbook.
APA format is not required, but solid academic writing is expected.
You are not required to submit this assignment to Turnitin.
Hereditary Influences
Evidence for hereditary influences on intelligence comes from the following observations:
- Family studies show that intelligence tends to run in families.
- Twin studies show a higher correlation between identical twins in IQ than between fraternal twins. This holds true even when identical twins reared apart are compared to fraternal twins reared together.
- Adoption studies show that adopted children somewhat resemble their biological parents in intelligence.
Family studies, twin studies, and adoption studies, however, are not without problems. See pages 36-–38 for more information about the drawbacks of such studies.
Hereditary Influences
Evidence for hereditary influences on intelligence comes from the following observations:
- Family studies show that intelligence tends to run in families.
- Twin studies show a higher correlation between identical twins in IQ than between fraternal twins. This holds true even when identical twins reared apart are compared to fraternal twins reared together.
- Adoption studies show that adopted children somewhat resemble their biological parents in intelligence.
Family studies, twin studies, and adoption studies, however, are not without problems. See pages 36-–38 for more information about the drawbacks of such studies.
Heritability is a mathematical estimate that indicates how much of a trait’s variation in a population can be attributed to genes. Estimates of the heritability of intelligence vary, depending on the methods used. Most researchers believe that heritability of intelligence is between 60 percent and 80 percent.
Heritability estimates apply only to groups on which the estimates are based. So far, heritability estimates have been based mostly on studies using white, middle-class subjects. Even if heritability of IQ is high, heredity does not necessarily account for differences between groups. Three important factors limit heritability estimates: