Figure 4.

Reinforcement effects of behaviour up and down the social ladder. (a) Positive and (b) negative reinforcement leading to increasing and decreasing social dominance with age at different life stages. Each pillar (phenotypic state, dominance and the ability to secure resources) will positively affect the next pillar, causing an upward spiral with age (a). Physiological state deteriorates with age owing to senescence, ultimately turning the direction of the effects (b). (Online version in colour.)