Title |
What Explains the Heritability of Completed Fertility? Evidence from Two Large Twin Studies
|
---|---|
Published in |
Behavior Genetics, August 2016
|
DOI | 10.1007/s10519-016-9805-3 |
Pubmed ID | |
Authors |
Daniel A. Briley, Felix C. Tropf, Melinda C. Mills |
Abstract |
In modern societies, individual differences in completed fertility are linked with genotypic differences between individuals. Explaining the heritability of completed fertility has been inconclusive, with alternative explanations centering on family formation timing, pursuit of education, or other psychological traits. We use the twin subsample from the Midlife Development in the United States study and the TwinsUK study to examine these issues. In total, 2606 adult twin pairs reported on their completed fertility, age at first birth and marriage, level of education, Big Five personality traits, and cognitive ability. Quantitative genetic Cholesky models were used to partition the variance in completed fertility into genetic and environmental variance that is shared with other phenotypes and residual variance. Genetic influences on completed fertility are strongly related to family formation timing and less strongly, but significantly, with psychological traits. Multivariate models indicate that family formation, demographic, and psychological phenotypes leave no residual genetic variance in completed fertility in either dataset. Results are largely consistent across U.S. and U.K. sociocultural contexts. |
X Demographics
Geographical breakdown
Country | Count | As % |
---|---|---|
United States | 6 | 19% |
United Kingdom | 2 | 6% |
Germany | 1 | 3% |
Bosnia and Herzegovina | 1 | 3% |
Spain | 1 | 3% |
Unknown | 20 | 65% |
Demographic breakdown
Type | Count | As % |
---|---|---|
Members of the public | 25 | 81% |
Science communicators (journalists, bloggers, editors) | 4 | 13% |
Scientists | 1 | 3% |
Practitioners (doctors, other healthcare professionals) | 1 | 3% |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
Croatia | 1 | 3% |
Unknown | 36 | 97% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Researcher | 8 | 22% |
Student > Master | 5 | 14% |
Student > Ph. D. Student | 4 | 11% |
Other | 3 | 8% |
Student > Bachelor | 3 | 8% |
Other | 5 | 14% |
Unknown | 9 | 24% |
Readers by discipline | Count | As % |
---|---|---|
Psychology | 9 | 24% |
Social Sciences | 8 | 22% |
Agricultural and Biological Sciences | 2 | 5% |
Economics, Econometrics and Finance | 2 | 5% |
Nursing and Health Professions | 1 | 3% |
Other | 4 | 11% |
Unknown | 11 | 30% |