Gowdy & Krall's (G&K's) insights into the impact of agriculture on economic organization help explain humanity's current crises of ecological degradation and growing inequality. Their work also contributes to the scientific understanding of human behavior, cultural evolution, and economic organization that will be required to develop an economic system capable of addressing these crises. I would suggest, however, that fossil fuel use and monetary exchange have taken human ultrasociality and economic organization in new directions. The emergence of an information economy may do the same, and it could possibly facilitate the re-emergence of more egalitarian and cooperative forms of economic organization.

The modern capitalist economy emerged not with the transition to agriculture, but rather, simultaneously with our ability to tap fossil fuel stocks (Farley Reference Farley, Heinberg and Lerch2010). The fossil fuel economy has taken division of labor, group size, growth, accumulation, and environmental domination to unprecedented extremes. The result is natural resource depletion, accumulating waste emissions, degradation of life-sustaining ecosystem services, overpopulation, and other existential threats to civilization.

Our current environmental challenges can all be characterized as prisoner's dilemmas: The best outcome for the individual is selfish behavior, regardless of what others do, but the best outcome for society is cooperation. The individual gains the benefits of excessive resource extraction or pollution, but shares the costs with society as a whole, and the costs imposed by any single individual are negligible. If others extract or pollute too much, each individual would be foolish not to, and if others refrain from doing so, the individual can free-ride on their efforts. Prisoner's dilemmas can be solved only through cooperation (Axelrod Reference Axelrod1984; Nowak & Highfield Reference Nowak and Highfield2011; Sober & Wilson Reference Sober and Wilson1998).

The modern economy is dominated by monetary exchange. Lea and Webley (Reference Lea and Webley2006) hypothesize that money, acting like a drug, has parasitized and corrupted the human instinct for reciprocal altruism. Simply priming individuals to think about money makes them less likely to offer help to others, solicit help, pursue social interaction, or behave ethically (Kouchaki et al. Reference Kouchaki, Smith-Crowe, Brief and Sousa2013; Vohs et al. Reference Vohs, Mead and Goode2006; Reference Vohs, Mead and Goode2008). Policies designed to appeal to self-interest, such as monetary rewards or punishments for certain behaviors, reduce the individual's motivations to act for the public good (Bowles Reference Bowles2008). Almost the inverse of ultrasociality, mainstream economic theory (MET) assumes self-regarding, individualistic behavior and methodological individualism. All social phenomena are analyzed as the result of individual actions. MET prioritizes individual freedom, and pursues the libertarian goal of satisfying unchanging, subjective individual preferences. In practice, simply studying MET appears to increase free-riding, selfish behavior, and even corruption (Cipriani et al. Reference Cipriani, Lubian and Zago2009; Frank & Schulze Reference Frank and Schulze2000; Frank et al. Reference Frank, Gilovich and Regan1993; Kirchgässner Reference Kirchgässner2005; Marwell & Ames Reference Marwell and Ames1981; Wang et al. Reference Wang, Malhotra and Murnighan2011). Modern monetary capitalism may prove incapable of solving prisoner's dilemmas.

Humans, however, are obviously capable of cooperation and altruism as well as competition and selfishness. Multilevel selection (MLS) offers a convincing theoretical explanation of why both types of behavior evolved. Though markets may promote selfish behavior, other institutions exist that stimulate voluntary cooperation and altruism (Axelrod Reference Axelrod1984; Bowles & Gintis Reference Bowles and Gintis2004; Boyd et al. Reference Boyd, Gintis, Bowles and Richerson2003; Fehr & Fishchbacher Reference Fehr and Fishchbacher2002; Fehr & Gächter Reference Fehr and Gachter2000; Gächter Reference Gächter, Frey and Stutzer2007; Gintis Reference Gintis2000; Gintis et al. Reference Gintis, Bowles, Boyd and Fehr2005). While MLS theory suggests that stimulating cooperation between groups can be difficult (Sober & Wilson Reference Sober and Wilson1998; Wilson Reference Wilson2007), ultrasocial species can share group identity for populations of hundreds of millions. It may be possible to evolve institutions that promote group cooperation on the scale necessary to solve our most serious global challenges. However, a single culture that strived for sustainability by reducing fossil energy use would be at the mercy of those that did not.

Many types of ultrasocial economic organization may coevolve with cultural and technological change. A monetary fossil fuel economy is very different from a pre-monetary agricultural one. Our ultrasocial species may now be transitioning to an information economy. All economic production requires information as well as natural resources and energy. Solving the problems of resource scarcity, waste emissions, and ecological degradation will almost certainly require technological breakthroughs, perhaps on the scale of agriculture and fossil fuels. Solar energy must be one of these technologies. Unlike fossil fuels, solar energy is not depleted through use, while the information required to capture it actually improves through use. Freely sharing information therefore facilitates technological advance. Once a useful technology exists, especially for a green technology, its value is maximized when all are free to use it (Farley & Perkins Reference Farley, Perkins and Robertson2013). Market economies, however, have created intellectual property rights to incentivize the private production of knowledge. But scientists competing for a new patent will not share information, and they will unnecessarily replicate research efforts, raising the costs of technological innovation. Once an innovation exists, charging royalties reduces use, and hence societal benefits: For example, if royalties drive the price of clean energy too high, industries may continue to burn coal to the detriment of all. An information economy is more efficient when organized around cooperative provision and open access rather than competition and price rationing (Benkler Reference Benkler2002; Farley & Kubiszewski Reference Farley, Kubiszewski and Hepting2015; Kubiszewski et al. Reference Kubiszewski, Farley and Costanza2010).

Speaking speculatively, any country could potentially initiate the transition to a new type of ultrasocial economic organization by sharing its green technologies with others on the condition that all further improvements would also be shared. The legal structure for this, copy-lefting, already exists (Mustonen Reference Mustonen2003). Generosity stimulates reciprocity. Countries might begin cooperating to protect the environment instead of competing for a larger share of dwindling ecological capacity. Non-cooperators could be penalized with high trade tariffs and economic sanctions. Reciprocity for generous acts and punishment for non-cooperation increase cooperation (Nowak & Highfield Reference Nowak and Highfield2011). The Internet is already democratizing access to information, contributing to the foundation of this new and potentially more cooperative form of social organization. Whether economic organization follows this or another path, G&K's insights into the ultrasocial nature of our current economy may help us nudge cultural evolution in a more sustainable direction.