about nature-nurture and why we should care about them

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Reynard Bond
5 years ago
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1 Three new puzzles about nature-nurture debates and why we should care about them

2 Heritability e.g. Heritability of IQ is 80 % meaning?

3 Heritability e.g. Heritability of IQ is 80 % meaning? genes have more influence on IQ than environment?

4 Heritability e.g. Heritability of IQ is 80 % meaning? genes have more influence on IQ than environment? changing genes has more influence on IQ than changing environment?

5 Puzzle 1 The two-part argument and the IQ paradox

6 Paradox of large gains in av. IQ test score between generations IQ generation 1 generation 2 time

7 IQ group 1 group 2

9 Puzzle 2 The possibility of underlying heterogeneity

10 Location L1 L2 L3 L4 L5 L6 L7 L8 Twin Pair TP1 TP2 TP3 TP4 TP5 TP6 TP7 TP8 MZT MZT MZT aabbccddee // FgHiJ MZT genet (pairs

11 underlying heterogeneity = heterogeneity of genetic & envtl. factors underlying devt. of trait Location L1 L2 L3 L4 L5 L6 L7 L8 Twin Pair TP1 TP2 MZT AAbbccDDee // FghiJ TP3 TP4 TP5 MZT genetic factors (pairs of alleles) sequence of environmental factors TP6 MZT aabbccddee // FgHiJ TP7 TP8 MZT

12 Application of human heritability if underlying heterogeneity is possible?? Location L1 L2 L3 L4 L5 L6 L7 L8 Twin Pair TP1 TP2 MZT AAbbccDDee // FghiJ TP3 TP4 TP5 MZT genetic factors (pairs of alleles) sequence of environmental factors TP6 MZT aabbccddee // FgHiJ TP7 TP8 MZT

13 Puzzle 3 Confusing terms and methods borrowed from breeding

14 Heritability e.g. Heritability of IQ is 80 % meaning? genes have more influence on IQ than environment? changing genes has more influence on IQ than changing environment?

15 Heritability e.g. Heritability of IQ is 80 % meaning? genes have more influence on IQ than environment? changing genes has more influence on IQ than changing environment? variation among means of genetic varieties (averaged across all locations) > variation of means of locations (averaged over all varieties)

16 variation among location means Mean across l1 l2 l3 l4 l5 l6 l7 l8 all varieties & replicates Location Mean across Variety all locations & replicates v A A v B B v C v D v E C D E v F F v G v H G H

17 Puzzle 3 Confusing terms and methods borrowed from breeding

19 Puzzle 2 The possibility of underlying heterogeneity

20 Application of human heritability if underlying heterogeneity is possible?? Location L1 L2 L3 L4 L5 L6 L7 L8 Twin Pair TP1 TP2 MZT AAbbccDDee // FghiJ TP3 TP4 TP5 MZT genetic factors (pairs of alleles) sequence of environmental factors TP6 MZT aabbccddee // FgHiJ TP7 TP8 MZT

21 Underlying heterogeneity not recognized as significant

22 From typological thinking to recognizing possible underlying heterogeneity mean group A in location a efs gfs mean group B in location b

23 From typological thinking to recognizing possible underlying heterogeneity mean group A in location a efs gfs mean group B in location b

24 From typological thinking to recognizing possible underlying heterogeneity efs gfs efs gfs spread of values for group A in location a spread of values for group B in location b mean group A in location a efs gfs mean group B in location b

25 From typological thinking to recognizing possible underlying heterogeneity efs gfs efs gfs spread of values for group A in location a spread of values for group B in location b mean group A in location a mean group B in location b efs gfs Q: Why treat observations this way?

26 From typological thinking to recognizing possible underlying heterogeneity spread of values for group A in location a spread of values for group B in location b

27 From typological thinking to recognizing possible underlying heterogeneity spread of values for group A in location a spread of values for group B in location b gf2 A A A A A A B A B B B B B B genetic factors for groups A & B ef2 b b b b b a ba a b a b a a a a environmental factors for groups in locations a & b gf1 ef1

28 From typological thinking to recognizing possible underlying heterogeneity spread of values for group A in location a spread of values for group B in location b gf2 A A A A A A B A B B B B B B genetic factors for groups A & B ef2 b b b b b a ba a b a b a a a a environmental factors for groups in locations a & b gf1 ef1 Q: How to expose these factors?

29 Puzzle 1 The two-part argument and the IQ paradox

30 reciprocal causation models adulthood (or when trait is measured) small variation birth Y0 Y 1 Y2 ranking among adults correlates with ranking at birth, yet generation to generation trends can occur Matching and Reciprocal causation growing up in environments whose differences (Y0...Y 1...Y 2...) in part match differences in the trait (or in underlying traits) at each stage of life & in part are given by transient non-matching influences. In addition, every individual's environment (Ys) follows society-wide trends that result from average of all individuals' changes. matching of environments + social multiplier

31 From typological thinking to recognizing possible underlying heterogeneity spread of values for group A in location a spread of values for group B in location b gf2 A A A A A A B A B B B B B B genetic factors for groups A & B ef2 b b b b b a ba a b a b a a a a environmental factors for groups in locations a & b gf1 ef1

Partitioning Genetic Variance

PSYC 510: Partitioning Genetic Variance (09/17/03) 1 Partitioning Genetic Variance Here, mathematical models are developed for the computation of different types of genetic variance. Several substantive