An evolutionary biologist has publicly challenged statements made by anthropologist Michael P. Masters during a recent appearance on Joe Rogan‘s podcast, saying the academic spread significant misinformation about human s*xual development.
Colin Wright, an evolutionary biologist, took to social media to address what he described as two major factual errors in Masters‘ discussion with podcast host Joe Rogan. The corrections center on fundamental aspects of human embryonic development and a rare medical condition affecting children in certain isolated populations.
The first disputed claim involves a common but incorrect belief about early human development. During the podcast episode, Masters stated that
“we all start out as females in utero and then maleness is imposed on the developing fetus.”
Wright countered that this represents a widespread misconception about biology.
According to Wright, humans actually begin development in a s*xually undifferentiated state with bipotential gonads, not as females. S*xual differentiation occurs around weeks six through eight of embryonic development, he explained. The distinction may seem subtle but represents an important clarification about how human biology actually works versus popular but inaccurate narratives.
The second correction addresses Masters‘ description of children on
“an island in the Pacific”
who are supposedly born female and transform into males at puberty. Masters told Rogan that these children
“are girls”
and described how their
“ovaries descend as testicles”
during adolescence.
Wright identified the location Masters likely referenced as either Papua New Guinea or more commonly a village named Salinas in the Dominican Republic. However, he emphasized that Masters fundamentally mischaracterized the medical condition involved.
According to Wright, these children are not girls who become boys. Instead, they are males who appear female at birth due to a genetic condition known as 5-alpha-reductase deficiency. The condition affects approximately one in 170 male births in Papua New Guinea and roughly one in 90 male births in Salinas.
The genetic condition prevents the body from producing sufficient DHT while in the womb, which is necessary for developing male external genitalia. Wright noted that athletes Caster Semenya and Imane Khelif share this same condition.
Contrary to Masters‘ description on the podcast, Wright clarified that these individuals are not born with ovaries that later transform into testicles. Rather, they are born with internal testes that descend at puberty, when they also develop a penis. They are boys with a difference of s*xual development that frequently results in them being incorrectly recorded as female at birth.
During the podcast conversation, Masters described the condition in dramatic terms.
“So you think puberty is hard enough already? These people turn into the opposite s*x at age like 12 or 13,”
he told Rogan.
When pressed about the appearance of these children before puberty, Masters insisted:
“They look like girls. Exactly like girls. They are girls.”
Masters attributed the prevalence of this condition to genetic drift in isolated island populations.
“A lot of times on islands you get really strange characteristics of people because of the isolation and those characteristics get selected just through genetic drift alone because it’s a small population,”
he explained.
He suggested that the trait likely originated with one person who was
“insensitive to dihydrotestosterone”
and then spread throughout the population over time. Masters also noted that natural selection would not necessarily work against this trait, calling it simply unusual rather than disadvantageous.
When asked about the specific location, Masters mentioned:
“I think it’s Malo Island and Vanuatu or something.”
He said he first learned about the phenomenon during his graduate studies at Ohio State University.
There are ongoing concerns about scientific accuracy in popular media, particularly when complex biological topics are discussed on widely viewed platforms. The Joe Rogan Experience reaches millions of listeners, making factual precision especially important when discussing scientific matters.
