"Until now, economic growth theory did not have implications for evolutionary biology, and evolutionary biology did not have implications for economic growth," said lead theorist Oded Galor, professor of economics at Brown University.
This new theory, the first of its kind ever proposed in the economics literature, appears as the lead article in the current Quarterly Journal of Economics. It is co-authored by Omer Moav of the Hebrew University of Jerusalem.
"The struggle for survival that had characterized most of human existence stimulated a process of natural selection and generated an evolutionary advantage to human traits that were complementary to the growth process, triggering the takeoff from an epoch of stagnation to sustained economic growth," the authors wrote in their study.
The evolution of the human brain in the transition to Homo sapiens "increased the evolutionarily optimal investment in offspring's quality," said Galor. "This was due to the complementary relationship between brain capacity and the return to investment in human capital."
The process gave an evolutionary advantage to people who had higher valuation toward offspring's quality, Galor said. "The subsequently increased prevalence of this genetic trait in the population ultimately permitted the Industrial Revolution to trigger a transition to a state of sustained economic growth."
The critical natural selection that occurred prior to the Industrial Revolution involved the fundamental tradeoff between child-caring and child-rearing. The "epoch of stagnation" gave an evolutionary advantage to a higher-quality smaller family rather than to lower-quality larger families, Galor said.