Figure 1.

Relationships between the mean ± s.e. relative ranks based on the outcomes of (a) play as pups and later agonistic (dominance) interactions as yearlings (n = 148 males, shown as filled-in circles and 122 females, shown as open circles) and (b) play as immature (pups or yearlings) and agonistic interactions for those same individuals as 2 year old adults (n = 32 males and 67 females as pups and yearlings. Ranks for adults are pooled because we detected no sex difference (see text). Relative ranks based on play are shown separately for pups (open circles, n = 97) and yearlings (filled-in circles, n = 102) to account for differences between life-history stages. Because dominance ranks increased as during between as age of adults increased, data shown here are limited to the first year of adulthood.