Cultural niche construction with application to fertility control: A model for education and social transmission of contraceptive use

The evolution of a cultural trait may be affected by niche construction, or changes in the selective environment of that trait due to the inheritance of other cultural traits that make up a cultural background. This study investigates the evolution of a cultural trait, such as the acceptance of the idea of contraception, that is both vertically and horizontally transmitted within a homogeneous social network. Individuals may conform to the norm, and adopters of the trait have fewer progeny than others. In addition, adoption of this trait is affected by a vertically transmitted aspect of the cultural background, such as the preference for high or low levels of education. Our model shows that such cultural niche construction can facilitate the spread of traits with low Darwinian fitness while providing an environment that counteracts conformity to norms. In addition, niche construction can facilitate the ‘demographic transition’ by making reduced fertility socially accepted.