The role of kinship in knowledge about medicinal plants: evidence for context-dependent model-based biases in cultural transmission?

ABSTRACT The similarity in traditional knowledge of medicinal plants was evaluated to draw inferences about the most important models for local knowledge transmission. The following questions were addressed: (1) Do related individuals possess greater similarity in knowledge of medicinal plants than unrelated individuals? (2) Do related individuals of the same generation possess greater similarity in knowledge than do related individuals of different generations? Semi-structured interviews were conducted on the medicinal plants known by the residents of a rural community in western Bahia. Mann-Whitney tests were used to compare Jaccard similarity values between related and unrelated individuals and between relatives of the same generation and relatives of different generations. Related individuals were found to have more similar knowledge than unrelated individuals, and relatives of the same generation were found to have more similar knowledge than relatives of different generations. These findings suggest that there are factors that favor cultural transmission between relatives of the same generation other than just vertical transmission.