I read an interesting piece in the New Scientist (Barras, 2020) about the role of warfare in developing complex civilisations.
The researchers (Turchin et al., 2022) quantitatively tested several theories using a general dynamic model based on the theoretical framework of cultural macroevolution and the Seshat: Global History Databank.
They tested 17 potential predictor variables proxying mechanisms suggested by major theories of sociopolitical complexity (and >100,000 combinations of these predictors).
Their research suggests the best-supported model indicates a strong causal role played by a combination of increasing agricultural productivity and invention/adoption of military technologies (most notably, iron weapons and cavalry in the first millennium BCE).
Barras, C. (2022) Did Warfare Give Rise To Complex Civilisations? New Scientist. 02 July 2022, pp.14.
Turchin, P., Whitehouse, H., Gavrilets, S., Hoyer, D., Francois, P., Bennett, J.S., Feeney, K.C., Peregrine, P., Feinman, G., Korotayev, A., Kradin, N., Levine, J., Reddish, J., Cioni, E., Wacziarg, R., Mendel-Gleason, G. & Benam, M. (2022) Disentangling the Evolutionary Drivers of Social Complexity: A Comprehensive Test of Hypotheses. Science Advances. 8(25), pp.eabn3517. https://www.science.org/doi/10.1126/sciadv.abn3517.