FIGURE 2.

Jensen's inequality effect on the interpretation of difference in group seed production between kin pairs and non‐kin pairs. Plants in non‐kin pairs have lower degrees of genetic similarity and thus tend to have larger differences in competitive ability, leading to larger differences in plant sizes (e.g., M_N1 for the weak competitor and M_N2 for the stronger competitor) associated with larger differences in seed productions (e.g., P_N1 and P_N2; and their averaged seed production ${\overline{P}}_N$ will be ${\overline{P}}_N=\left(P_{N1}+P_{N2}\right)/2$). On the other hand, plants in kin pairs tend to have a similar plant size (M_K) associated with a similar level of seed production (P_K). When the group total mass (e.g., 2M_K in a kin pair, and M_N1 + M_N2 in a stranger pair) is determined by the total amount of available resources in the group and the correlation between plant size and seed production follows a saturation curve, for a given amount of resources at the group level (i.e., M_N1 + M_N2 = 2M_K), the group seed production of plants in non‐kin pairs will be inevitably lower than that in kin pairs (i.e., $P_{N1}+P_{N2}=2{\overline{P}}_N<2P_K$) [Colour figure can be viewed at wileyonlinelibrary.com]