Reciprocal cooperation is the act of working together with another individual to increase the likelihood that the other individual will continue to work together during future encounters. Reciprocal cooperation can be explained evolutionarily because it promotes the fitness of individuals in certain conditions. Cooperation is most commonly studied in humans. However less complex mammals such as rats display cooperative behaviors in certain conditions. This study examines the necessary conditions for cooperation in rats by testing the significance of housing conditions and prior interactions between cooperating rats. We found that rats did not cooperate at levels greater than chance
