Adoptive & biological families with 30-year-old offspring: Proportion of variance in IQ attributable to environmentally mediated effects of parental IQs was estimated at .01; heritability was estimated to be 0.42

Genetic and environmental contributions to IQ in adoptive and biological families with 30-year-old offspring. Emily A. Willoughby, Matt McGue, William G. Iacono, James J. Lee. Intelligence, Volume 88, September–October 2021, 101579. https://doi.org/10.1016/j.intell.2021.101579

Highlights

• Genetic and environmental sources of variance in IQ were estimated from 486 adoptive and biological families

• Families include 419 mothers, 201 fathers, 415 adopted and 347 biological fully-adult offspring (M age = 31.8 years; SD = 2.7)

• Proportion of variance in IQ attributable to environmentally mediated effects of parental IQs was estimated at .01 [95% CI 0.00, 0.02]

• Heritability was estimated to be 0.42 [95% CI 0.21, 0.64]

• Parent-offspring correlations for educational attainment polygenic scores show no evidence of adoption placement effect

Abstract: While adoption studies have provided key insights into the influence of the familial environment on IQ scores of adolescents and children, few have followed adopted offspring long past the time spent living in the family home. To improve confidence about the extent to which shared environment exerts enduring effects on IQ, we estimated genetic and environmental effects on adulthood IQ in a unique sample of 486 biological and adoptive families. These families, tested previously on measures of IQ when offspring averaged age 15, were assessed a second time nearly two decades later (M offspring age = 32 years). We estimated the proportions of the variance in IQ attributable to environmentally mediated effects of parental IQs, sibling-specific shared environment, and gene-environment covariance to be 0.01 [95% CI 0.00, 0.02], 0.04 [95% CI 0.00, 0.15], and 0.03 [95% CI 0.00, 0.07] respectively; these components jointly accounted for 8% of the IQ variance in adulthood. The heritability was estimated to be 0.42 [95% CI 0.21, 0.64]. Together, these findings provide further evidence for the predominance of genetic influences on adult intelligence over any other systematic source of variation.

Keywords: IntelligenceAdoptionHeritabilityVocabularyPolygenic scores

Asking the mayor's office how to start a business: Chinese & German cities responded to 36-37% requests; American cities responded to 22%; Chinese cities were more responsive to requests from men

Köhler, Ekkehard A. and Matsusaka, John G. and Wu, Yanhui, Street-Level Responsiveness of City Governments in China, Germany, and the United States (August 19, 2021). SSRN: http://dx.doi.org/10.2139/ssrn.3907862

Abstract: This paper presents evidence from parallel field experiments in China, Germany, and the United States. We contacted the mayor’s office in over 6,000 cities asking for information about procedures for starting a new business. Chinese and German cities responded to 36-37 percent requests; American cities responded to only 22 percent of requests. We randomly varied the text of the request to identify factors that affect the likelihood of receiving a response. American and German cities were more responsive to requests from citizens than foreigners; Chinese cities did not discriminate on this basis. Chinese cities were more responsive to requests from men than women; German cities did not discriminate on this basis and American cities had a slight bias in favor of women. Cities in all three countries were more responsive to requests associated with starting a construction business than a green business, but especially Chinese cities. Chinese cities were more responsive when the mayor was being considered for promotion than after a promotion decision, suggesting the importance of promotion incentives in China, but low responsiveness to green investment suggests limited incentives for environmental improvement. We argue that the response patterns are consistent with simple political economy theories of democracy and autocracy.

Keywords: Responsiveness, bureaucracy, democracy, autocracy, environment, discrimination, China, Germany

JEL Classification: H7, H83, O38, P5, R5