1. Do Assortative Mating Patterns for IQ Block Upward Social Mobility? Wendy Johnson University of Edinburgh William G. Iacono and Matt McGue University of Minnesota April 19, 2014

3. Assortative Mating for IQ Generally runs.3 to.4 Source is most likely educational assortment – Rather than IQ directly – Increases genetic variance and population stratification Generally assumed to be stable across the range of IQ, but what if not? – Interesting social phenomenon in own right – Would especially stratify population where highest

4. Minnesota Twin Family Study Longitudinal study of two cohorts of twins – One recruited age 11 (1260 pairs), one age 17 (635 pairs) – Return basically every 3 years – IQ assessed (abbreviated WAIS/WISC) ages 11, 17, 25 in twins, intake in parents – Very population-representative; recruited from population records with ~80% participation, high retention over time

5. Correlations 11-yo17-yo Midparent-twins IQ At 11.480 At 17.527.440 At 25.531 Twins' IQ over time 11-17.785 17-25.807 11-25.720 Twins IQ by zygosity MZ at 11.750 DZ at 11.504 MZ at 17.829.809 DZ at 17.517.505 MZ at 25.778 DZ at 25.480 Midparent IQ-ed.578.571 Midparent IQ-SES.513.520 Midparent ed-SES.739.773 Twins' IQ-midparent ed At 11.316 At 17.349.326 At 25.351 Twins' IQ-SES At 11.287 At 17.334.296 At 25.331 Mom-dad IQ.341.322

6. Another Correlation Higher parent’s IQ-absolute value of difference in parents’ IQs: –.515 in 11-yo –.605 in 17-yo Some examples: – 151-118, 151-110, 147-134, 146-121, 145-121, 145-121, 144-129, 143-100, 143-117, 142-105 – 77-77, 78-78, 78-76, 79-77, 80-74, 81-75, 81-79, 82-76, 83-81, 83-73, 84-72, 84-83, 84-80, 85-72

8. Why? Above 100, higher up you are, fewer there are like you – But people with high IQ tend to be successful at what they’re doing and attractive partners to people in the more heavily populated lower parts of the distribution Low IQs are relatively rare too – But people in these ranges not so attractive to people in more heavily populated parts of the distribution – And less likely to participate in scientific studies

9. IQ and SES Gibson, J. B. (1973). Journal of Biosocial Science, 5, p. 254, Data from three Cambridge-based studies.

10. IQ and Earnings Murray, C. (1997). Public Interest, 28, p. 23. Data from NLSY.

11. Social Mobility? Murray, 1997

12. More Correlations

13. Socioeconomic status modifies heritability of IQ in young children Author(s): Turkheimer, E; Haley, A; Waldron, M; et al. Source: PSYCHOLOGICAL SCIENCE Volume: 14 Issue: 6 Pages: 623-628 DOI: 10.1046/j.0956- 7976.2003.psci_1475.x Published: NOV 2003 Times Cited: 302 (from All Databases)302

14. Social Class, Solipsism, and Contextualism: How the Rich Are Different From the Poor Author(s): Kraus, MW (Kraus, Michael W.) 1 ; Piff, PK (Piff, Paul K.) 2 ; Mendoza-Denton, R (Mendoza-Denton, Rodolfo) 2 ; Rheinschmidt, ML (Rheinschmidt, Michelle L.) 2 ; Keltner, D (Keltner, Dacher) 2Kraus, MW 1Piff, PK 2Mendoza-Denton, R 2Rheinschmidt, ML 2Keltner, D 2 Source: PSYCHOLOGICAL REVIEW Volume: 119 Issue: 3 Pages: 546-572 DOI: 10.1037/a0028756 Published: JUL 2012 Times Cited: 0 (from Web of Science) Cited References: 234 [ view related records ] Citation Map 234view related records Abstract: Social class is shaped by an individual's material resources as well as perceptions of rank vis-a-vis others in society, and in this article, we examine how class influences behavior. Diminished resources and lower rank create contexts that constrain social outcomes for lower-class individuals and enhance contextualist tendencies that is, a focus on external, uncontrollable social forces and other individuals who influence one's life outcomes. In contrast, abundant resources and elevated rank create contexts that enhance the personal freedoms of upper-class individuals and give rise to solipsistic social cognitive tendencies that is, an individualistic focus on one's own internal states, goals, motivations, and emotions. Guided by this framework, we detail 9 hypotheses and relevant empirical evidence concerning how class-based contextualist and solipsistic tendencies shape the self, perceptions of the social environment, and relationships to other individuals. Novel predictions and implications for research in other socio-political contexts are considered. Intelligence Author(s): Sternberg, RJ (Sternberg, Robert J.)Sternberg, RJ Source: WILEY INTERDISCIPLINARY REVIEWS-COGNITIVE SCIENCE Volume: 3 Issue: 5 Pages: 501-511 DOI: 10.1002/wcs.1193 Published: SEP-OCT 2012 Times Cited: 0 (from Web of Science) Cited References: 72 [ view related records ] Citation Map 72view related records Abstract: Intelligence is the ability to learn from past experience and, in general, to adapt to, shape, and select environments. Aspects of intelligence are measured by standardized tests of intelligence. Average raw (number-correct) scores on such tests vary across the life span and also across generations, as well as across ethnic and socioeconomic groups. Intelligence can be understood in part in terms of the biology of the brainespecially with regard to the functioning in the prefrontal cortex. Measured values correlate with brain size, at least within humans. The heritability coefficient (ratio of genetic to phenotypic variation) is between 0.4 and 0.8. But genes always express themselves through environment. Heritability varies as a function of a number of factors, including socioeconomic status and range of environments. Racial-group differences in measured intelligence have been reported, but race is a socially constructed rather than biological variable. As a result, these differences are difficult to interpret. Different cultures have different conceptions of the nature of intelligence, and also require different skills in order to express intelligence in the environment.

16. 100 Generations of Corn Breeding Hill, W. G. (2005). Science, 307, 683 – 684, adapted from Dudley, J. W., & Lambert, R. J. (2004). Plant Breeding Reviews, 24, Part 1, 79.