Science Friday

Autism Rates Appear To Be Even Across Sexes. Diagnosis Is Not

February 21, 2026

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  • A Swedish study tracking millions of individuals from 1985 to 2022 suggests the actual prevalence of autism is nearly even across sexes, contrary to the long-held belief of higher prevalence in boys. 
  • Autistic individuals assigned female at birth are often diagnosed significantly later than their male counterparts, with diagnoses catching up rapidly in adolescence, leading to an equal 1:1 ratio by age 20. 
  • Late or missed autism diagnoses are associated with profoundly negative life impacts, including self-blame, struggles across life domains, and higher suicide rates, highlighting the critical need for improved and neurodiversity-affirmative diagnostic criteria. 

Segments

Introduction to Autism Sex Differences
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(00:01:13)
  • Key Takeaway: The established CDC statistic of autism being three times more common in boys is being challenged by new research.
  • Summary: Host Flora Lichtman introduces the episode’s focus on challenging the long-held idea that autism is significantly more prevalent in boys than girls. A new study tracking millions of Swedish individuals found the prevalence of autism is actually even across sexes. However, people assigned female at birth are often diagnosed later in life.
Analyzing Swedish Diagnosis Data
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(00:02:01)
  • Key Takeaway: The sex difference in autism diagnosis shrinks significantly for older cohorts, reaching a 1:1 ratio by age 20.
  • Summary: Epidemiologist Dr. Caroline Fyfe explains that the three-to-one sex difference remains stable in children under 10 but decreases markedly in older groups. Diagnoses for girls catch up rapidly during adolescence, with the average age of diagnosis being 15 to 19 for girls versus 10 to 14 for boys. The study did not account for transgender or non-binary individuals.
Diagnostic Criteria Implications
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(00:04:20)
  • Key Takeaway: Historical research based primarily on male presentations may have influenced diagnostic criteria, suggesting a need for broader understanding of female autism manifestation.
  • Summary: Dr. Fyfe suggests the historical focus on male-centric autism research may have influenced diagnostic criteria interpretation. She advocates for extending research to better understand how autism manifests in girls. The host notes this aligns with historical patterns of medical sexism.
Impact of Late Autism Diagnosis
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(00:05:31)
  • Key Takeaway: Undiagnosed autistic individuals often internalize their struggles as personal failings, leading to complex mental health issues and increased suicide risk.
  • Summary: Dr. Rachel Moseley confirms that being missed for diagnosis has a profoundly negative impact, causing individuals to blame themselves for life struggles without an explanation. This self-blame is linked to higher suicide rates among autistic people, who identify improved diagnosis as a suicide prevention strategy.
Differences in Female Presentation
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(00:07:21)
  • Key Takeaway: Autistic girls often present closer to non-autistic peers in childhood, masking difficulties that become starker as social demands increase.
  • Summary: Autistic girls present outwardly more similarly to non-autistic peers in childhood compared to autistic boys, partly due to masking behaviors. Their social understanding difficulties remain equal to boys, but the gap widens as puberty and complex social relationships strain masking efforts. Interests in girls are often relational (people, celebrities) rather than the highly specific, non-relational interests seen in many autistic boys.
Redesigning Diagnostic Frameworks
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(00:10:29)
  • Key Takeaway: Future diagnostic criteria should shift from a purely symptom/disorder focus to a neurodiversity-affirmative, strengths-based approach.
  • Summary: Dr. Moseley advocates for updating diagnostic criteria to reflect current knowledge about neurodiversity, moving beyond symptom checklists. She suggests explaining autism using a strengths-based approach, acknowledging areas of challenge alongside unique autistic strengths. This shift in framing is crucial for how individuals receive and internalize their diagnosis.
Personal Experience of Diagnosis
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(00:15:00)
  • Key Takeaway: For Dr. Moseley, receiving a late diagnosis at age 28 served as a profound vindication, reframing years of perceived personal failure.
  • Summary: Dr. Moseley shares that she was considered for an autism diagnosis as a child but never formally assessed, leading her to believe she was fundamentally flawed or even a psychopath. Learning about autism in women later in life prompted her to seek a private diagnosis, which she describes as a ‘verdict of not guilty.’ She emphasizes that society must stop ‘breaking’ autistic people by recognizing neurological variety.