The number of trials during which tool transfer occurred in experiment 1 (24 trials per subjects).

The first line represents the pairs (Ai: Ai, Ay: Ayumu, Ch: Chloe, Cl: Cleo, Pn: Pan, Pl: Pal, Pe: Pendesa, Pu: Puchi, Ma: Mari). The second line represents the relationship between the pairs (M: mother, O: offspring, D: dominant, S: subordinate). The third line represents the overall number of trials in which a participant transferred a tool to the partner. The remaining three lines below represent the number of each type of tool transfer observed.