Fig. S1: Help provided by each focal rat to previously cooperating and defecting partners from Relatedness decreases and reciprocity increases cooperation in Norway rats

The graph shows the frequency of donations provided by focal individuals to related or unrelated partners that had been cooperating or defecting during the experience phase. Each line shows the behaviour of on focal rat to the same partner. Focal rats provided more food to cooperating than defecting partners, and the overall level of help was increased when interacting with unrelated partners. When lines completely overlapped, we raised one of them slightly to make them visible and marked the lines with asterisks.