A population consists of two types, “friendlies” and “aggressives.” Each individual interacts with a randomly chosen member of the population. When two friendlies interact, each earns 3 units. When two aggressives interact, each earns 0 units. When a friendly and an aggressive interact, the former gets a payoff of 1 unit, the latter a payoff of 5 units. The growth rate of each type is proportional to its average payoff. What will be the equilibrium population shares of each type?