SFI Omidyar Fellow Kaleda Denton began her fellowship at SFI in July, 2024. (image: Douglas Merriam)

Humans’ complex cultures — our beliefs and biases, traditions and fads — can develop through interactions with each other and with our environments. SFI Complexity Postdoctoral Fellow Kaleda Denton studies how cultural traits arise and spread, exploring the role of non-genetic processes in human evolution. “There’s a lot going on that affects human evolution besides the spread of biologically advantageous traits,” Denton says. “It’s not just about genes: phenotypes can be influenced by the environment, epigenetics, development, and culture.”

Denton completed a Ph.D. in Biology at Stanford University, modeling cultural evolution by focusing on conformity. “Many previous models for conformity are binary, considering only two variants” says Denton. “Is a person cooperative, or selfish? This kind of modeling doesn’t allow for a more complex investigation of conformity.” 

Old models study conformity around this type of binary questioning, able to answer questions like who drinks coffee and who doesn’t. Denton models conformity in more nuanced ways, allowing the quantitative study of cultural traits with many variants, such as infant names. A society where 1 out of every 2 babies are named Bob would be a strangely uniform society — but a binary model can’t process a plurality of Bobs any more than it can model what drinks people are enjoying instead of coffee, or how humans can be selfish sometimes and cooperative other times.

“We developed a model for conformity to many variants,” Denton says, “and were able to explore how they spread, which could be much different from the binary-trait case.” At SFI, she plans to continue her study of the role of non-genetic processes in evolution, including not only cultural evolution but also development and epigenetic regulation. She is interested in the role of enforcement in maintaining cooperative systems, from societies to cells. She began her fellowship in July.