Contractualism and cooperative rationality
Contractualist reasoning seems crucial to creating the flexible and spontaneous agreements
that help us manage social interactions outside the moral domain. Indeed, social
interactions require intricate coordination of thought and behavior, which raises
a fundamental cognitive challenge: how are different individuals able to formulate
and play their part in the same plan, so that their thoughts and actions cohere smoothly?
Imagine one person, A, moving to one side to allow another, B, to pass down the aisle
of a crowded train carriage. This coordination problem could be resolved in several
ways. Instead of moving aside, A might temporarily sit in an empty seat. B might
move past cautiously, at speed, with or without thanks. A and B might play opposite
roles. How do both parties align on the same plan, often without communicating? A
could attempt to second-
A recent proposal is that such joint reasoning involves a process of “virtual bargaining” (Misyak et al., 2014). Each person figures out what would happen if both parties were able to reach an agreement through discussion and negotiation. They then follow their part in the hypothetical virtual bargain. Suppose that B is pushing a drinks trolley. If A and B were to discuss explicitly, they might conclude that A should move aside. If the conclusion of this hypothetical bargaining process is “obvious”, then A may immediately do this — and the interaction is managed successfully. Crucially, the hypothetical agreement to follow this plan has normative force. If A violates the “obvious” agreement and barges ahead, B may complain, likely backed up by bystanders. Notice that the bargain is created “in the moment” to best meet the needs of the immediate circumstances, and its normative force comes from its status as the natural tacit agreement (Melkonyan et al., 2022) between reasonable people. Following the virtual bargain is, in a sense, the “appropriate” or “right” course of action; violating it is reprehensible. This line of argument suggests that at least some of our actions in morally relevant contexts might arise from the creation and enforcement of such ephemeral “social contracts in miniature” (Zeitoun et al., 2022). Thus, even the simplest and most fleeting social interactions can have an ethical flavor.
Arthur le Pargneux; Nick Chater; and Hossam Zeitoun (2024) – “Contractualist tendencies and reasoning in moral judgment and decision making”
The model of contractualist reasoning of Le Pargneux, Chater, and Zeitoun (2024)
is a simple one: we act together with others according to explicitly negotiated agreements,
or according to as-
In the present account, this is because what we would agree to is cooperatively rational, maximising benefits/wellbeing for each person concerned, constrained by impartiality.
If a partner is required to deviate from this in order for the overall goal to be achieved, they might have to make a sacrifice, in which case it is expected that they will be thanked, praised, rewarded, etc., by the others.
In other words, the phenomena we observe consistent with contractualism are not caused by contracts or contractualism, but by cooperative rationality, which is also consistent with contracts and contractualism, because we would agree to cooperatively rational behaviour and results if we could.
The point is, why are people cooperatively rational? Why do I want to maximise “your” benefits and wellbeing as well as my own? What are the conditions that lead to this kind of psychology?
Instrumental “I” rationality
If a course of action is instrumentally rational, then it means that it is aimed at maximising my own benefits and well being.
Cooperative “we” rationality
When two or more people come together to collaborate, even in fleeting circumstances, they form a collaborative “we”. The model of cooperative rationality is that “we” govern “you” and “I”, according to norms, on behalf of “us”, i.e., in the direction of maximising mutual well being (Tomasello, 2016). Moral norms are methods of achieving, maintaining or restoring mutual well being (Perry, 2026).
Therefore, what “we” want coincides with what “we” would explicitly agree to – impartial, maximal mutual benefit.
Coordination using social norms
A social norm is a way of being cooperative in otherwise competitive situations (Tomasello,
2016). Strangers can navigate fleeting, though complex, social interactions using
social norms that address common coordination problems and that the whole group knows
in common ground knowledge. An example is queuing to receive some in-
A social norm is therefore like a moral norm, in that both are aimed at mutual benefit or well being (through cooperation). A social norm aims at conflict reduction through a fair and impartial distribution of benefits and well being, that no partners could legitimately complain about, and that all (instrumentally and cooperatively rational) parties would agree to if negotiated explicitly.
When you and I collaborate, perhaps to coordinate passing each other in a narrow train carriage, we form a collaborative “we” that takes a “bird’s eye view” of the collaboration and its roles, and these roles are filled with interchangeable personnel. The role is important, not the specific person.
Social norms and their enforcement are “three-
Hence, social norms are impartial.
Other-
Humans are great apes. Compared with humans, the other great apes are selfish and not very cooperative or altruistic, and they don’t like to share.
Humans are thought to have evolved in small groups where all productive members shared resources with the whole group. This means that humans evolved to need, to depend upon, others in the vicinity. This need produces empathic concern for the one who is needed. If I am valuable to you, then you have concern for my welfare. Helping me is helping yourself.
Humans have taken these evolved altruistic instincts into the modern world, so that
today, we tend to feel empathic concern for all humans (if we feel they are deserving).
This motivates other-
“Recognition respect”
When prospective collaborative partners come together, they approach one another with an attitude of respect, since the bottom line is that each needs the other to play their part; and each demands respect as a valuable collaborative resource (Tomasello, 2016).
Additionally, in humans, it is a universal norm to treat others with respect; and it is a universal need that others should respect the self. The origin of this is that humans are vulnerable and therefore in need of being treated with dignity and respect; i.e., with human rights (Andorno and Baffone, 2014).
Fairness and cooperation
When people collaborate, they expect and are satisfied with fair, impartial and respectful treatment throughout. This is what they would agree to if they could. Therefore, in a scenario like the vignette of le Pargneux, Chater, and Zeitoun (2024), people don’t start fighting.
Fairness is built into the structure of cooperation: all partners’ interests are maximised impartially.
Gene’s eye view of impartiality
The evolution of cooperation requires that its benefits reach all contributing parties in roughly similar amounts. Natural selection works on every individual’s relative advantage compared with others; hence, gaining an absolute benefit is insufficient. If individuals were satisfied with any absolute benefit, they might still face negative fitness consequences if they were doing less well than competing others. It makes sense, therefore, to compare one's gains with those of others.
Sarah F Brosnan and Frans B M de Waal (2014) – “Evolution of responses to (un)fairness”
My fitness benefits can either be intrinsic or comparative: absolute or relative. Impartial fairness provides both kinds, as my benefits are maximised (absolute) while essential difference relative to others is minimised (relative).
References
Le Pargneux A; N Chater; and H Zeitoun (2024) – “Contractualist tendencies and reasoning in moral judgment and decision making”; Cognition. 2024 Aug; 249:105838. https://doi.org/10.1016/j.cognition.2024.105838 ; Epub 2024 Jun 1. PMID: 38824696
Perry, Simon (2026) – “Understanding morality and ethics”; https://orangebud.co.uk/web_book_2.html
Tomasello, Michael (2016) – “A Natural History of Human Morality”; Harvard University Press, Cambridge MA