Effects of intent (teaching vs accurate reproduction) on the cultural evolution of narratives

Abstract

In cultural transmission, information flows from ‘producers’ to ‘receivers’. Transmission biases such as content-, model- and frequency-based biases, which modulate the adoption of cultural traits by receivers, have been explored in depth. We focus instead on a bias on production and compare transmission fidelity when producers either intend to teach or intend to reproduce socially acquired information. Eighty participants were asked to read a story and reproduce it either in order to ‘teach it to someone else’ or just ‘recall it as accurately as possible’. In order to test whether differences in fidelity between these two tasks were related to information encoding (during reading) or to reproduction, we also manipulated the timing of instructions: Half of the participants were informed of the task (Teach or Recall) Before reding the story and the other half, After reading the story. Participants were arranged in 20 transmission chains of 4 generations. The first generation in each chain read a text about the environment (from Mesoudi et al., 2006), and subsequent generations read the previous participant’s output story. We measured two aspect of fidelity: Quantity and Accuracy of information retained over generations. We found that being informed of the task Before reading the story led to higher Accuracy and Quantity than being informed After reading. Surprisingly, Teaching yielded lower Accuracy than Recall, but both resulted in similar Quantity retained. Additional analyses revealed differences in the content of the information under Teaching and Recall. We conclude that aspects of cultural transmission pertaining to production, in particular, intention to teach vs reproduce, influence transmission dynamics and therefore need to be integrated in models of cultural evolution. Reference Mesoudi, A., Whiten, A., & Dunbar, R. (2006). A bias for social information in human cultural transmission. British Journal of Psychology, 97(3), 405–423.