[4] When he was 12, his mother introduced him to Charles Darwin's The Descent of Man, and Selection in Relation to Sex, which encouraged his later interest in human evolution.

[6] In 1983, Thornhill published The Evolution of Insect Mating Systems, a book that journalist Ethan Watters described as "groundbreaking".

Thornhill has also suggested that pathogen defense could help explain civil and ethnic warfare, homicide, patriarchal family structures, and social suppression of female sexuality.

[3] In 2021, Thornhill appeared as a guest on episode 38 of season 4 of the Jordan B. Peterson Podcast entitled: Death, Disease, and Politics.

There, he discussed his research and views with the host (Peterson) about a range of topics, including attractiveness, Thornhill's parasite-stress theory, and the “critical role that infectious disease plays in humanity, IQ, sex, religion, and conservatism”.