Transmission bias refers to the psychological tendencies of individuals to favor specific cultural variants rather than others. There are two common biases, conformist bias that is a specific kind of frequency-dependent copying strategy wherein individuals adopt the most common cultural variant with a probability that is higher than its actual frequency in the population, and payoff-bias that generally applies to the type of copying strategy wherein the probability of adopting a cultural variant depends on some observed payoff.

Prof. Hong presented a new model that combines both frequency dependent bias (including conformist bias) and payoff bias in a single decision-making calculus. By approximating polynomial equations, Prof. Hong derived a stable polymorphic equilibrium with the two cultural variants.

Prof. Hong’s work provides a new angle for the transmission biases in cultural evolution. For example, his results showed that an inter-mediate level of conformity may be most adaptive and may spontaneously evolve as it resists the invasion of low-payoff variants yet enables the fixation of high-payoff variants in the population. The work also offers new insights for understanding how human being employ individual strategies in particular learning instances.