Philosophy Phriday: The Puzzle of Inter-Group Cooperation

The Daily Ant hosts a weekly series, Philosophy Phridays, in which real philosophers share their thoughts at the intersection of ants and philosophy. This is the fiftieth contribution in the series, submitted by Dr. Helen De Cruz.

The Puzzle of Inter-Group Cooperation:
What Ants Can Tell Us, and What it Means for Brexit and Trade Wars

Humans and ants share a peculiar characteristic that is rare in the animal world: both are prone to habitually cooperate not just within their groups, but also between groups.

Between-group cooperation raises evolutionary and philosophical puzzles: Under what circumstances can inter-group cooperation arise? Why don’t individuals from different groups just fuse into one bigger group, if cooperation is so useful to them? How can we make sure that such cooperative ventures continue? I’ll here look at what we can learn from polydomy—the phenomenon of different ant nests that cooperate while maintaining separate nest identity—parallels between this and human institutions such as NATO, NAFTA, and the EU, and I will draw some implications for trade wars and Brexit.

Irodomyrmex purpureus with a purpose. Photo: Bill and Mark Bell/Flickr

To understand between-group cooperation, it is useful to look at why animals often aggregate in groups (shoals of fish, lion prides, wolf packs etc.). Martin Nowak has argued that cooperation, rather than merely a puzzle to be solved, is one of the forces through which evolution works, together with variation and selection. A slightly less controversial take on this is Szathmáry and Maynard Smith who argue that complexity is not an inevitable evolutionary pathway, but that it is the result of a series of evolutionary transitions that involve increased cooperation and division of labor. Working together requires organisms to relinquish some autonomy, as we can see in early evolutionary transitions that gave rise to the eukaryotic cell (e.g., the division of labor between mitochondrial DNA and nuclear DNA), and now more recently in the spectacular division of labor in human groups that allows for high levels of cultural complexity, allowing people to become scholars, musicians, warriors, or baristas, rather than having to hunter, gather or farm. The evolution of multicellular life on Earth is the story of how organisms increasingly work together, relinquishing autonomy, drawing strength in numbers, and becoming more and more complex.

Animals don’t live in groups because it is more fun or convenient. There are significant costs to living in groups (e.g., the risk of being lowly ranked, increased competition for food and mates), but overall group living can be favored when it affords protection from predation, from outside competitors for the same resources, and from harsh or unpredictable environmental conditions. In the face of external threats, group size can increase if several groups fuse together into a larger one. But in ants and human groups, individual groups can and often do maintain their own group identity, for instance, by maintaining mostly intra-group reproduction.

Multiple nests of Iridomyrmex purpureus (meat ants) for example, will often pool together to defend against echidna attacks on one of the nests. In polydomous ant colonies of Formica lugubris (hairy wood ants), food sharing can also take place in case of food asymmetries, where nests rich in resources distribute the food to poorly provisioned ones. Resource asymmetries and external threats are the main explanations for why different ant nests cooperate without thereby relinquishing their individual group characteristics. Each nest still has a queen, and workers mainly stay within their own nests.

Formica lugubris formed lugubriously, perhaps. Photo: Wikimedia

In humans, cooperation between groups in one domain can lead to closer cooperation in others, for instance, economic cooperation can give rise to more aligned political institutions. This is why the precursor of the EU, the EEC with the Treaty of Rome in 1957, deliberately engineered an “ever closer union” among the peoples of Europe, starting out with closer economic ties. As we can read in the preamble of that treaty, the founders of the EEC wished to “strengthen the unity of their economies and to ensure their harmonious development by reducing the differences existing between the various regions and the backwardness of the less favoured regions.” This provisioning of less well off groups also occurs in ants, but the extensive division of labor does not.

Indeed, there are two key differences between inter-group cooperation with ants and humans. Ants typically do not engage in buffering, which is a form of risk management whereby groups help each other in time of need. This requires a form of delayed reciprocity (if group A helps B, and B helps C, there is the expectation that C would help A or B if they are in need) and cultural institutions, which are beyond what ants can do.

A second key difference is that, as far as we can tell, different ant groups do not engage in division of labor. In many cooperative units, human groups (while maintaining their within-group characteristics) relinquish some form of autonomy through division of labor. Take a simple trade agreement, whereby two groups trade with each other goods that are easier to produce by them, in exchange for goods that are easier to produce for the other group. Over time, the groups will increasingly come to rely on each other for these goods and decrease their own production. This increased inter-reliance creates interdependence of groups which is highly complex but largely invisible to those who are part of it.

An interdependant world. Photo: My Modern Met

Just how interconnected groups can become is exemplified by the myriad unexpected effects of Brexit, which even its most ardent supporters did not foresee in the lead up to the Referendum on the UK’s membership of the EU. The move of the European Banking and Medicine Agencies, a foreseeable side effect of the decision to leave the EU, took Brexiters by surprise. The questions of how the UK will obtain isotopes for cancer treatment outside Euratom, or how they’ll be able to negotiate an alternative to the Open Skies agreement, or replace the trade losses through exiting the Single Market and the Customs Union, let alone how to resolve the status of the Northern Irish border, or sort out the rights of frontier workers and citizen in the UK and the EU, remain a muddle, with only about a year remaining to the exit date. Similarly, Trump’s threat of trade wars will be tricky to say the least, with the prospect of everyone involved losing out as a result. As Kuper observed, Brexit can be seen as a large naturalistic experiment on itself, for the edification of other nations: can the UK go it alone? We will soon find out.

Long-term cooperation between human groups is potentially unstable. Due to increased interdependence and division of labor, smaller groups can merge into one large group, and individual identities of groups can erode over time, as when smaller territories merge into a nation state or a united states. Conversely, there can be a dissolution of the groups that cooperate into smaller units when the connections between them are lost or deliberately severed. Ethnographic evidence suggests that intergroup relationships such as trade are maintained through religious ceremonies (e.g., in late prehistoric Chile) or through ceremonial gift giving (e.g., among the Ache and Hadza). Such non-utilitarian movements are crucial in establishing trust: for example, among the Ache in Paraguay, adults form stable, long-term relationships with members of the same gender from other groups: they have ritual names for each other and perform rituals concerning birth and puberty of each other’s children. These ceremonial roles come with rights and obligations for mutual support, and thus tie different Ache groups to each other. Ceremonies enable people from different groups to meet each other outside of the purely utilitarian exchange of resources, and to establish trust.

These ethnographic examples suggest that successful intergroup cooperation, in spite of the increased dependence it creates, requires effort to cement. Perhaps, with long-term intergroup relationships at risk in the UK and the US, this is something we can learn from. Successful nation states have established traditions of non-utilitarian ceremonies to consolidate cooperation. These include Independence Day celebrations, flags, and national anthems at sports events—indeed the sport events themselves can be thought of as a form of ceremonies where people identify with the nation states through the teams that represent them. But intergroup cooperation also requires such non-utilitarian ceremonial links, as the ethnographic examples show. In ants, intergroup cooperation can be sustained through common threats and inclusive fitness (the nests in polydomous colonies still have a relatively high degree of relatedness); in humans, there is the added complexity of division of labor. In humans, intergroup cooperation provides an interesting middle way between fusion of large groups and fission into smaller groups, requiring a constant building of trust between members.

17349819_1314272995327829_6840823034087721029_oDr. Helen De Cruz is Associate Professor (Senior Lecturer) of philosophy at Oxford Brookes University. She specializes in philosophy of cognitive science, philosophy of religion, and experimental philosophy. Her publications include the monograph (co-authored with Johan De Smedt) A Natural History of Natural Theology: The Cognitive Science of Theology and Philosophy of Religion (MIT Press, 2015), the monograph Religious Disagreement (forthcoming with CUP), and the edited volume (co-edited with Ryan Nichols) Advances in Religion, Cognitive Science, and Experimental Philosophy (Bloomsbury Academic, 2016). She has also published papers in Philosophical Studies, Australasian Journal of Philosophy, Ergo, American Philosophical Quarterly, and other venues. Currently, she is principal investigator on the Templeton-funded project Evolution, ethics, and human origins: A deep-time perspective on human morality (2017-2020).