Cross-country relationships between life expectancy, intertemporal choice and age at first birth

Cross-country relationships between life expectancy, intertemporal choice and age at first birth. By Adam Bulley & Gillian Pepper
Evolution and Human Behavior, http://www.ehbonline.org/article/S1090-5138(17)30007-7/abstract

Abstract: Humans, like other animals, typically discount the value of delayed rewards relative to those available in the present. From an evolutionary perspective, prioritising immediate rewards is a predictable response to high local mortality rates, as is an acceleration of reproductive scheduling. In a sample of 46 countries, we explored the cross-country relationships between average life expectancy, intertemporal choice, and women's age at first birth. We find that, across countries, lower life expectancy is associated with both a smaller percentage of people willing to wait for a larger but delayed reward, as well as a younger age at first birth. These results, which hold when controlling for region and economic pressures (GDP-per capita), dovetail with findings at the individual level to suggest that life expectancy is an important ecological predictor of both intertemporal and reproductive decision-making.