Human brain evolution in a Malthusian economy

Chu, Angus C. (2023): Human brain evolution in a Malthusian economy. Forthcoming in: Macroeconomic Dynamics

Abstract

Why did the human brain evolve? This study develops a Malthusian growth model with heterogeneous agents and natural selection to explore the evolution of human brain size. We find that if the cognitive advantage of a larger brain dominates its higher metabolic costs, then the average brain size increases over time, which is consistent with the rising trend in human brain size that started over 2 million years ago. Furthermore, an improvement in hunting-gathering productivity (e.g., the discovery of using stone tools and fire in hunting animals and cooking food) helps to trigger this human brain size evolution. As the average brain size increases, the average level of hunting-gathering productivity also rises over time. Quantitatively, our model is able to replicate the trend in hominin brain evolution over the last 10 million years.

• Item Type: MPRA Paper
• Language: English
• Keywords: Natural selection; brain size evolution; Malthusian growth theory
• Subjects: N - Economic History > N1 - Macroeconomics and Monetary Economics ; Industrial Structure ; Growth ; Fluctuations; O - Economic Development, Innovation, Technological Change, and Growth > O1 - Economic Development > O13 - Agriculture ; Natural Resources ; Energy ; Environment ; Other Primary Products; Q - Agricultural and Natural Resource Economics ; Environmental and Ecological Economics > Q5 - Environmental Economics > Q56 - Environment and Development ; Environment and Trade ; Sustainability ; Environmental Accounts and Accounting ; Environmental Equity ; Population Growth

References

Ashraf, Q., and Galor, O., 2011. Dynamics and stagnation in the Malthusian epoch. American Economic Review, 101, 2003-2041.

Ashraf, Q., and Galor, O., 2018. The macrogenoeconomics of comparative development. Journal of Economic Literature, 56, 1119-1155.

Chu, A., 2023. Natural selection and Neanderthal extinction in a Malthusian economy. Journal of Population Economics, 36, 1641-1656.

Chu, A., Peretto, P., and Furukawa, Y., 2024. Evolution from political fragmentation to a unified empire in a Malthusian economy. Journal of Economic Behavior and Organization, 222, 284-293.

Chu, A., and Xu, R., 2024. From Neolithic Revolution to Industrialization. Macroeconomic Dynamics, 28, 699-717.

Collins, J., Baer, B., and Weber, E. J., 2014. Economic growth and evolution: Parental preference for quality and quantity of offspring. Macroeconomic Dynamics, 18, 1773-1796.

Dalgaard, C.-J., and Strulik, H., 2015. The physiological foundations of the wealth of nations. Journal of Economic Growth, 20, 37-73.

DeSilva, J.M., Traniello, J.F.A., Claxton, A.G., and Fannin, L.D., 2021. When and why did human brains decrease in size? A new change-point analysis and insights from brain evolution in ants. Frontiers in Ecology and Evolution, 9: 742639.

Fa, J., Stewart, J., Lloveras, L., and Vargas, J., 2013. Rabbits and hominin survival in Iberia. Journal of Human Evolution, 64, 233-241.

Fonseca-Azevedo, K., and Herculano-Houzel, S., 2012. Metabolic constraint imposes tradeoff between body size and number of brain neurons in human evolution. Proceedings of the National Academy of Sciences, 109, 18571-18576.

Galor, O., 2022. The Journey of Humanity: The Origins of Wealth and Inequality. Dutton.

Galor, O., and Klemp, M., 2019. Human genealogy reveals a selective advantage to moderate fecundity. Nature Ecology & Evolution, 3, 853-857.

Galor, O., and Michalopoulos, S., 2012. Evolution and the growth process: Natural selection of entrepreneurial traits. Journal of Economic Theory, 147, 759-780.

Galor, O., and Moav, O., 2002. Natural selection and the origin of economic growth. Quarterly Journal of Economics, 117, 1133-1191.

Galor, O., and Ozak, O., 2016. The agricultural origins of time preference. American Economic Review, 106, 3064-3103.

Gonzalez-Forero, M., and Gardner, A., 2018. Inference of ecological and social drivers of human brain-size evolution. Nature, 557, 554-557.

Gowlett, J. A. J., 2016. The discovery of fire by humans: A long and convoluted process. Philosophical Transactions of the Royal Society B: Biological Sciences, 371, 20150164.

Grabowski, M., 2016. Bigger brains led to bigger bodies?: The correlated evolution of human brain and body size. Current Anthropology, 57, 174-196.

Hansson, I., and Stuart, C., 1990. Malthusian selection of preferences. American Economic Review, 80, 529-544.

Heldstab, S.A., Isler, K., Graber, S.M., Schuppli, C., van Schaik, C.P., 2022. The economics of brain size evolution in vertebrates. Current Biology, 32, R697-R708.

Lagerlof, N.-P., 2007. Long-run trends in human body mass. Macroeconomic Dynamics, 11, 367-387.

Lynn, R., 1990. The evolution of brain size and intelligence in man. Human Evolution, 5, 241-244.

Malthus, T.R., 1798. An Essay on the Principle of Population. Oxford World's Classics.

Ofek, H., 2001. Second Nature: Economic Origins of Human Evolution. Cambridge University Press.

Robson, A., 2001. The biological basis of economic behavior. Journal of Economic Literature, 39, 11-33.

Robson, A., and Kaplan, H., 2003. The evolution of human life expectancy and intelligence in hunter-gatherer economies. American Economic Review, 93, 150-169.

Rogers, A., 1994. Evolution of time preference by natural selection. American Economic Review, 84, 460-481.

van Valen, L., 1974. Brain size and intelligence in man. American Journal of Biological Anthropology, 40, 417-423.

Villmoare, B., and Grabowski, M., 2022. Did the transition to complex societies in the Holocene drive a reduction in brain size? A reassessment of the DeSilva et al. (2021) hypothesis. Frontiers in Ecology and Evolution, 10: 963568.