Autism spectrum disorder (ASD) refers to a range of conditions characterized by challenges with social skills, repetitive behaviors, speech and nonverbal communication. Autism affects boys more often than girls, with a ratio of about 4:1. However, autism presents differently in girls than boys. Girls are often diagnosed later, as autism tends to look different in females. This article will explore at what age signs of autism tend to emerge in girls.
When are children typically diagnosed with autism?
The average age for an autism diagnosis is around 4 years old. However, autism can be reliably diagnosed as early as age 2. According to the Centers for Disease Control and Prevention (CDC), the median age for an ASD diagnosis is:
- 52 months for boys
- 55 months for girls
So while the median age of diagnosis is slightly later for girls, the difference is fairly small – only 3 months. This indicates that clear signs of autism do tend to emerge around ages 4-5 years for both genders.
However, there are some key differences in when autism symptoms first become noticeable in boys versus girls. Let’s explore this more.
Early red flags in boys
Research shows that autism is often detected earlier in boys than girls. Here are some common early red flags for autism that may be noticed in preschool aged boys:
- Limited or no eye contact
- Delayed speech or lack of language development
- Repetitive behaviors like lining up toys
- Not responding to their name
- Difficulty interacting or playing with peers
- Fixated interests or obsessions
Many of the early signs of autism in boys involve social communication challenges. Boys with autism often have a harder time interacting with others or communicating nonverbally. These types of impairments become very evident between ages 2-4, leading to earlier detection.
Early red flags may be missed in girls
In contrast, the early symptoms of autism in girls tend to be less obvious to parents and doctors. Here are some reasons why autism goes undiagnosed for longer in girls:
- Girls may have milder restricted/repetitive behaviors
- Girls are often quieter, less disruptive in groups
- Girls have more socially approved interests
- Girls may be better at masking social challenges
Young girls on the spectrum are often able to compensate for their social difficulties better than boys. For example, a girl might observe her peers and mimic their social behavior. Or she might retreat and play alone when unsure how to interact. Her symptoms may fly under the radar until social demands exceed her capabilities.
When delays become more apparent in girls
While some symptoms may be noticeable earlier, most girls tend to be diagnosed with autism later than boys. Delays in social communication often emerge more clearly when girls reach school-age, around 5-8 years old.
At this age, interactions become more complex with peers and teachers. Classroom learning is very social and girls on the spectrum struggle to keep up socially and academically. Here are some red flags that often arise for girls with autism around ages 5-8:
- Difficulty making and keeping friends
- Withdrawal from social situations
- Reluctance to join group activities
- Avoiding chit chat or “small talk”
- Taking things very literally
- Misreading social cues
- Learning challenges despite intellectual ability
Once girls with ASD reach school-age, social skill deficits become more pronounced. They have a harder time navigating increasingly complex peer relationships. Their communication challenges also make academics more of a struggle. These issues often lead to an autism diagnosis between ages 5-8.
Puberty brings added challenges
The middle school and teen years bring another round of challenges for girls on the autism spectrum.
Puberty is an exceptionally difficult period, as social nuances and peer dynamics become highly complex. Girls with autism often feel entirely overwhelmed trying to fit in and interact appropriately. They simply lack the innate social instincts of neurotypical girls. Common struggles include:
- Isolation and difficulties maintaining friendships
- Getting bullied or ostracized by classmates
- Depression and anxiety
- Withdrawn behavior
- Coping through repetitive/soothing behaviors
If autism has not yet been identified, the middle and high school years bring heightened difficulties. Diagnosis often occurs during adolescence as a girl can no longer compensate adequately for core social deficits.
Average age of diagnosis in girls
While some girls do get diagnosed earlier, the average age of autism diagnosis for girls is:
- 8 years old for girls with intellectual disability
- 12 years old for girls without intellectual disability
So girls who have normal IQ/development tend to be diagnosed much later on average. Their intelligence enables them to mask symptoms for longer. Yet as social/academic demands increase, eventually their underlying challenges are revealed. By their teens, as social interactions and peer relations peak in complexity, girls with high-functioning autism simply cannot hide their core deficits any longer.
Why does autism go undiagnosed in girls?
There are several reasons why autism often goes unnoticed and undiagnosed for longer in girls:
Less severe symptoms
On average, girls on the spectrum have less severe autism symptoms. They tend to have:
- Milder repetitive/restricted behaviors
- More subtle difficulties with nonverbal communication
- Better ability to mimic social interactions
So their symptoms may not visibly impair functioning until later ages. Learning and academics can help mask the condition initially. But by puberty, as social demands escalate, girls no longer compensate adequately.
Better camouflaging skills
Studies show that girls are better at camouflaging or masking autism symptoms. Common camouflaging tactics include:
- Observing peers and mimicking their mannerisms/conversations
- Avoiding social situations due to confusion or anxiety
- Suppressing natural behaviors to fit in
- Using conversational scripts copied from others
Camouflaging allows girls to disguise their social difficulties and get by socially. However, it ultimately takes a tremendous toll causing isolation, anxiety, and depression.
Diagnostic biases
Unfortunately, gender biases also contribute to missing autism in girls. Doctors are more tuned into the symptoms boys display. They may discount difficulties socializing or sensory issues in girls as normal shyness or anxiety. Identifying autism requires an experienced clinician with specific training in female presentation.
Improving early identification in girls
To improve early detection, parents and doctors should watch for these red flags for autism in young girls:
- Unusual or intense interests, like memorizing facts about a topic
- A strong need for routines and order
- Unusual sensory behaviors like smelling toys or objects
- Motor delays including late walking or clumsiness
- Delayed language development and unusual speech patterns
- Difficulties making age-appropriate eye contact
In addition, standardized screening tools at well child visits can catch early signs. The M-CHAT R/F is one validated tool that can be used for screening young girls.
Looking for developmental gaps, like advanced reading ability with lagging social skills, is another important indicator. Paying attention to subtle social deficits and insisting on specialist evaluation is key to identifying at-risk girls sooner.
Conclusion
While some girls do show signs of autism in toddlerhood, most tend to be diagnosed later than boys. Milder symptoms, better camouflaging skills, and diagnostic biases contribute to this gender gap. Core social and communication challenges often emerge more visibly at school-age or beyond for higher functioning girls on the spectrum. Increased awareness and screening can help identify girls earlier so they can access needed supports. With appropriate intervention, girls with autism can thrive socially and academically.