Fig. 2.

Summary of model dynamics. In mode M₁, all children receive ρ = 1, regardless of their mothers' cultural beliefs. Thus, in M₁, sex ratio r always increases. In mode M₀, all children receive ρ = 0, and r always decreases. In M_σ, a child's ρ follows his/her mother's cultural belief σ_s. In this mode, direction and rate of change in r is determined by the effect of parental and societal intuitive preferences (ρ) on the transmission of cultural belief (σ_s), i.e., parameters C₀₁, C₁₀, V₀₁ and V₁₀.