Summary: A large -scale study of more than 2,500 young children found no significant clinical differences in autistic features between men and women at the time of early diagnosis. Made for two decades, the study used comprehensive evaluations between language, motor skills, cognitive features and social behaviors.
The only difference noted was a slight advantage for women in the daily skills of life, based on parents’ reports. These findings suggest that sex differences in autism can later arise in development instead of the beginning of symptoms.
Key facts:
Without early sex differences: autistic young children showed almost identical clinical profiles, regardless of sex. Only a remarkable exception: women obtained slightly higher scores in the daily skills of life based on parents’ reports. Development girls typically stand out: small female without autism surpassed men in language and social skills.
Source: UCSD
Men have more than four times more likely to receive a diagnosis of autism than women.
But a new study conducted by researchers from the UC School of Medicine San Diego has not found clinical differences in autistic features among sexes in young children when autism is diagnosed for the first time.
The study was published in the human behavior of nature on May 26, 2025. The findings have potential implications for early diagnosis and intervention for autistic children.
Between 2002 and 2022, the researchers evaluated more than 2,500 male and female children between 12 and 48 months of age. Of these young children, 1,500 were autistic, 600 typically developed and 475 development was delayed.
The evaluations included 19 different measures of language development, social and motor skills, features of central autism, such as repetitive behaviors, cognitive skills and other development characteristics.
The study also examined social attention using eye monitoring technology. All evaluations were carried out in one site, the UC San Diego Autism Excellence Center, by licensed clinical psychologists.
The researchers found:
There are no clinical differences among autistic male and female children in all metrics except one of the metrics. The only exception was a measure of the daily development of life skills based on parents’ reports, such as dressing and feeding themselves, in which women obtained slightly higher scores than men. When they were grouped into low, medium and high capacity subtypes between autistic spectra based on robust art state methods, there were no different clinical differences between males and differences between males and clinical women. When the researchers followed the development trajectory in autistic children over time. Flexed sex differences among children delay in development.
Several previous studies with less than 100 participants have shown differences between the sexes in autistic children.
However, the current study is the largest and most complete of its kind to date, and one of the few studies to evaluate children with autism at a very early age, according to Senior author Karen Pierce, PH.D., professor of neurosciences and director of the Center for Excellence of Autism at the School of Medicine of UC San Diego.
“There is no consensus in the field on whether women are more or less impacted than men, and that is probably due to the fact that there have been no large -scale studies as soon as possible,” Pierce said.
“Based on previous small studies, we had anticipated that there would be some sex differences. So we were surprised not to find anything at all.”
However, researchers found sex differences among women’s and male children that typically, with women who perform at significantly higher levels than men in more than half of the tests, especially those who measure social skills, language development and daily skills.
“This is consistent with literature; small women seem to develop a little faster than men in terms of their linguistic capacity and social capacity and how well they perform daily life skills: adaptive things for a two -year -old child,” Pierce said.
“Typical developing females accelerate in their development in relation to men.”
Pierce says that the findings for autistic children without clinical differences between men and women at the time of the first start of autism lead to two possible conclusions.
“One is that previous studies that report sex differences are incorrect, perhaps due to the small sample size, sampling bias, limited study measures or other methodological problems,” he said.
“An alternative conclusion is that sex differences do not exist at the time of the first beginning, but that they emerge slowly at later ages, driven by psychosocial factors such as socialization or differences in biology that can be developed through development.”
To examine this alternative possibility, a high -quality large -scale study would be required that tracks autistic children from childhood to school age and beyond, according to Pierce.
Autism is highly inheritable, and Pierce says that findings have implications to understand the development of the condition, improve early detection and improve early intervention.
Because the study found that young children with autism are grouped into scientifically robust subtypes within the autistic spectrum instead of sex, believe that it can be preferable to focus on these differences when it seeks to understand clinical heterogeneity and the most appropriate interventions for each subtix, for example.
“If you can improve the language and communication of a small child at the younger age possible, then they will meet their needs better, and they can contribute to society more effectively, because they can do whatever they love to do,” Pierce said.
“It really is that each child reaches its maximum potential.”
The additional authors of the study include the first author Sanaz Nazari, the second senior author Eric Couchesne, Sara Ramos Cabo, Srinivasa Nalabolu, Cynthia Carter Barnes, Charlene Androason, Javad Zahiri, Ahtziry Esquive of medicine, and Diebe. and Michael V. Lombardo, in Italian isituto di Technology.
Financing: The study was financed, in part, by the National Institutes of Mental Health (subsidies R01MH118879, R01MH080134, R01MH10446, R01MH121595, P50-MH081755, R01MH11058, R01DC016385).
On this Autsim research news
Author: Susanne Bard
Source: UCSD
Contact: Susanne Bard – UCSD
Image: The image is accredited to Neuroscience News
Original research: open access.
“Large -scale examination of early age differences in neurotypic children and those with autistic spectrum disorder or other development conditions” by Karen Pierce et al. Nature Human behavior
Abstract
Large -scale exam of early age differences in neurotypic children and those with autistic spectrum disorder or other development conditions
Autistic spectrum disorder (ASD) is clinically heterogeneous, with continuous debates about phenotypic differences between boys and girls.
Understanding these differences, particularly at the age of the beginning of the first symptoms, is essential to advance early detection, discover etiological mechanisms and improve interventions.
Taking advantage of the Get Set Early program, we analyze a cohort of 2,618 young children (middle ages: ~ 27 months) through transverse, longitudinal and grouping analysis, made using statistical and automatic learning approaches, to evaluate sex differences in groups with ASD, delay of development and typical development through standardized and experimental measures, including a monitoring of the eyes.
The results did not reveal significant sex differences in young children with ASD in 17 of 18 measures, including the severity of symptoms based on the autism diagnostic observation program, a receptive and expressive language based on the Mullen Mullen scales of early learning and social attention based on the Geopref’s eye monitoring test.
In contrast, girls with typical development surpassed boys in several measures.
Subtype analysis stratify children in low, medium and high groups in a similar way they did not show sex differences in ASD.
In general, our findings suggest that phenotypic sex differences are minimal or non -existent in those with ASD at the time of the beginning of the first symptoms.
