Figure 4.

The order of solving in the smooth-coated otters for each of the six tasks. The total association of each naïve individual with informed individuals is plotted against the sequence of solving (task-solving event = 1 is when the first individual solved, etc.). Offspring are plotted as circles and parents as triangles. The individual that solved the task at each part of the sequence is plotted in red and joined with red lines. The dashed blue line shows the path we would expect the red line to take if there were no social transmission (but allowing that juveniles are faster to solve). If there is social transmission through the network the red line should be above the blue line. The solvers are labelled as Mum/Dad for parents and as Sis (sister)/Bro (brother) with ID number for offspring. In (a–d) tasks 1–4, the individual to solve the task next tends to be an offspring with a relatively high level of association to informed otters relative to others for that solve, and the red line is clearly above the dashed blue line. In (e–f) tasks 5–6, this pattern is no longer apparent.