William Costello

Evolutionary psychologist, incel expert

William Costello is an evolutionary psychologist and PhD researcher at the University of Texas whose fearless approach to taboo topics has made waves in the field of human mating psychology, sex differences, and modern dating dynamics.

Costello shot to prominence with his groundbreaking research on the psychology of incels (involuntary celibates)—a controversial yet often misunderstood online subculture. Instead of demonizing, he sought to understand, bringing an evolutionary perspective to modern dating struggles. His insights into online dating, sexual marketplaces, and shifting gender roles have since caught the attention of major media outlets.

A natural science communicator, William has appeared on some of the biggest podcasts in the space, including The Jordan Harbinger Show, The Psychology Podcast with Scott Barry Kaufman, and Modern Wisdom with Chris Williamson. His engaging, no-nonsense style makes complex psychological theories feel fresh, and deeply relevant to today’s dating landscape.

Beyond research, he’s on a mission to bridge the gap between academia and the real world—helping people better understand themselves and their relationships through the lens of evolutionary psychology. Whether he’s discussing why dating apps skew the sexual marketplace, why some men struggle in modern romance, or how evolutionary theory can explain our deepest desires, Costello is redefining how we think about human mating in the 21st century.

With his mix of intellectual rigor, media savvy, and a willingness to tackle uncomfortable truths, William Costello is fast becoming one of the most compelling voices in evolutionary psychology today.

Why did we invite him on?

Netflix’s recent hit Adolescence has captured the cultural zeitgeist like no TV show since Squid Game. The subject of incels and the ‘alt-right pipeline’ has never been more at the forefront of public discourse, and it’s welcomed a lot of bad actors. It’s not an issue to be taken lightly, and we wanted to have a serious, insightful discussion about the developing problem. We wanted to hear from an expert - someone who could give an unbiased, objective insight into the psychology of the group, and answer our questions about how the internet, politics and society fostered the phenomenon.

William has discussed the subject here on TRIGGERnometry before, but it seemed like the perfect time to revisit the subject. What does the show get right? What does it get wrong?

What did we learn?

”I hope the politicians who are interested pay attention to research rather than just the show.”

Already, Adolescence has a sociopolitical footprint. Not only have the Prime Minister and his fellow MPs praised it, but they’ve decided it warrants showing in UK schools. For this reason, we can’t dismiss concerns about its accuracy are unlike concerns for other works of art. To the next generation, Adolescence may prove to be as much about education as it is entertainment. William thinks the show has a great deal of merit, but worries that the wrong message might be taken from it - a shallow reading that leads to a spread of misinformation regarding the subject.

The perceived race-swapping of the main character has also been a source of ire in some circles. William isn’t concerned with this issue - the nature of co-creator Stephen Graham playing the father and the child actor being such a talent push back against arguments of ‘reverse-racism’ - but he is keen to set the record straight.