Christopher Ryan,Cacilda Jetha

About the author

Christopher Ryan, co-author of Sex at Dawn: The Prehistoric Origins of Modern Sexuality, is married to the book’s other author, Calcilda Jetha.

Prior to publishing his debut text, Ryan attended Saybrook University in San Francisco, California where he completed a Ph.D in psychology. Ryan’s doctoral thesis focused on the prehistoric roots of human sexuality, which ultimately became the basis of his writing.

Currently, Ryan hosts a popular podcast called Tangentially Speaking, which aims to inspire individuals to take stewardship of the planet.


Calcilda Jetha, co-author of Sex at Dawn: The Prehistoric Origins of Modern Sexuality and long-time spouse of Christopher Ryan, is a practicing psychiatrist with a focus in couples therapy and psycho-sexual disorders.

Jetha, who was born in Mozambique and fled with her family to Portugal amidst civil war, has conducted extensive research for the World Health Organization (W.H.O). Specifically, she studied sexual behaviors among rural Africans in order to help develop AIDS-preventions efforts for this population.

Calcilda Jetha and Christopher Ryan currently reside in Barcelona, Spain.