Primate Prosocial Behaviour as Socially Gated Action Selection

Research on prosocial behaviour in nonhuman primates faces two related but distinct problems. First, empirical findings are heterogeneous: studies report instrumental helping, targeted tool transfer, food provisioning, consolation, and collaborative action, whereas others report little or no concern for partner welfare in low-cost prosocial-choice paradigms. These differences may reflect paradigm-specific variation in recipient need, action cost, actor benefit, joint payoff, solicitation, relationship context, competition, affordance clarity, and response bias rather than disagreement about one mechanism. Second, the interpretive vocabulary is underconstrained. Terms such as altruism, empathy, prosocial motivation, helping, and collaboration are often defined from behavioural outcomes and then treated as if they identified distinct latent mechanisms. This manuscript proposes a computational reframing of the problem. Prosocial behaviour is formalised as socially gated action selection. In the model, instrumental helping, low-cost prosocial choice, costly recipient benefit, strict altruism-like outcomes, need-sensitive empathy-like responding, and coordinated joint action are task and outcome profiles generated by different configurations of independently specified variables. These include need detection, goal inference, affordance recognition, action cost, actor benefit, relationship and tolerance effects, competition, request context, social feedback, joint payoff, action selection, and motor or apparatus bias. An illustrative simulation shows how low-cost instrumental helping, cost- or risk-suppressed recipient benefit, false-positive prosocial choice, and reliable-partner collaboration can arise from the same architecture. The framework identifies which task variables must be measured or manipulated before stronger claims about other-regarding motivation, empathy-like responding, or collaboration are justified.