Cooperation

== Among other animals ==
Cooperation is common in non-human animals. Besides cooperation with an immediate benefit for both actors, this behavior appears to occur mostly between relatives. Spending time and resources assisting a related individual may reduce an organism's chances of survival, but because relatives share genes, may increase the likelihood that the helper's genetic traits will be passed on to future generations.<ref name="Hamilton">Hamilton, W.D. (1964). "The Genetical Evolution of Social Behaviour". ''Journal of Theoretical Biology'', 7, 1–16.</ref> The [[cooperative pulling paradigm]] is an experimental design used to assess if and under which conditions animals cooperate. It involves two or more animals pulling rewards towards themselves via an apparatus they can not successfully operate alone.<ref name="de Waal">de Waal, Frans (2016). "Are We Smart Enough To Know How Smart Animals Are?" {{isbn|978-1-78378-305-2}}, p. 276</ref>

Some researchers assert that cooperation is more complex than this. They maintain that helpers may receive more direct, and less indirect, gains from assisting others than is commonly reported. Furthermore, they insist that cooperation may not solely be an interaction between two individuals but may be part of the broader goal of unifying populations.<ref name="Clutton">Clutton-Brock, T. (2002). "Breeding together: Kin selection and mutualism in cooperative vertebrates". ''Science'', 296(5565), 69–72. {{doi|10.1126/science.296.5565.69}}</ref>