Testing reciprocity in social interactions: a comparison between the directional consistency and skew-symmetry statistics.

In the present article, we focus on two indices that quantify directionality and skew-symmetrical patterns in social interactions as measures of social reciprocity: the directional consistency (DC) and skew-symmetry indices. Although both indices enable researchers to describe social groups, most studies require statistical inferential tests. The main aims of the present study are first, to propose an overall statistical technique for testing null hypotheses regarding social reciprocity in behavioral studies, using the DC and skew-symmetry statistics (Phi) at group level; and second, to compare both statistics in order to allow researchers to choose the optimal measure depending on the conditions. In order to allow researchers to make statistical decisions, statistical significance for both statistics has been estimated by means of a Monte Carlo simulation. Furthermore, this study will enable researchers to choose the optimal observational conditions for carrying out their research, since the power of the statistical tests has been estimated.