Title of the paper: "The robustness of reciprocity: Experimental evidence that each form of reciprocity is robust to the presence of other forms of reciprocity"

Title of the paper: "The robustness of reciprocity: Experimental evidence that each form of reciprocity is robust to the presence of other forms of reciprocity" I think the interesting point about this paper isn't the conclusion, which is unsurprising, but rather the methods used for confirming it (They use linear mixed models, which I hadn't encountered before).