A new study has revealed that autistic children often show a strong interest in letters and numbers, although this inclination is frequently overlooked due to their preference for solitary activities.

During diagnostic evaluations, many autistic children naturally gravitate toward magnetic boards with letters and numbers. But just how common is this interest among autistic children? And what precisely characterizes this fascination?

To answer these questions, Alexia Ostrolenk, a researcher and graduate in psychiatric sciences from the Université de Montréal, conducted a large-scale study involving over 700 young children. This research was directed by Laurent Mottron, a professor in the Department of Psychiatry and Addiction at the Université de Montréal and a psychiatrist at the Rivière-des-Prairies Mental Health Hospital, CIUSSS du Nord-de-l’Île-de-Montréal. The team also included David Gagnon, a PhD candidate in psychiatry; Mélanie Boisvert, a student in psychiatric sciences; Océane Lemire and Marie-Pier Côté, both doctoral candidates in psychology at Université de Montréal; and Sophie-Catherine Dick, a doctoral candidate in psychology at Université de Sherbrooke.

The study received support from the Quebec Research Fund – Health sector (FRQS), the Transforming Autism Care Consortium (TACC), and the Marcel and Rolande Gosselin Research Chair in Cognitive Neuroscience of Autism.

Examining Over 700 Medical Records

The researchers reviewed medical records of children assessed for autism spectrum disorder (ASD) at the Rivière-des-Prairies Mental Health Hospital, affiliated with Université de Montréal, from 2018 to 2021. A total of 701 children, including 391 autistic children, all averaging four and a half years old, were included. “We examined whether psychiatrists and psychologists mentioned any elements related to an interest in letters or numbers in their reports,” says Alexia Ostrolenk.

They then conducted 45-minute phone interviews with 138 parents of autistic children, 99 parents of non-autistic children with atypical development, and 76 parents of neurotypical children. The interviews further explored children’s behaviors related to letters and numbers, asking questions such as whether the child sang the alphabet, played with letters, or asked to be read to, helping to distinguish social behaviors (like reading with an adult) from non-social behaviors (like writing alone).

A Marked Interest in Letters and Numbers

The results showed significant differences between autistic and non-autistic children concerning interest in letters and numbers. For example, 20% of reports indicated an intense or exclusive interest in letters among autistic children, compared to only 3% in the non-autistic group. Direct interviews revealed an even higher trend: 37% of autistic children showed intense or exclusive interest in letters, exceeding the 20% noted in clinical reports. “This 37% rate is substantial, especially considering that most autistic children are minimally verbal,” emphasizes David Gagnon.

Moreover, 17% of autistic children showed an intense or exclusive interest in numbers, compared to just 2% in the clinical non-autistic group, with autistic children being 3.49 times more likely to show a strong interest in numbers at the same age.

The findings also indicate that interest in letters and numbers emerges around the same time in both autistic and neurotypical children, at approximately 30 months versus 36 months, respectively.

A Less Noticed Interest Due to Solitary Activities

Autistic children’s interest in letters and numbers often involves solitary activities, making it less visible to parents. “Social behaviors are more noticeable to parents because they’re involved, like reading a book together. But non-social behaviors often consist of solitary activities that parents may not observe because they’re not part of it,” Alexia Ostrolenk explains.

“Some parents have even mentioned that their child doesn’t speak at all, but upon further questioning, they realize their child recites numbers or the alphabet,” adds Ostrolenk, highlighting the difference between parents’ perceptions and the behaviors they describe.

Interest in Letters Despite Language Delay

The results show that autistic children may develop an early competency with letters, even when they appear to have a marked delay in verbal language skills. “A child who doesn’t communicate verbally may still have a notable interest in letters, though not in a relational way,” explains David Gagnon.

The researchers speculate that linguistic knowledge accumulation in some autistic individuals might follow a different route. “There are anecdotes about autistic children who didn’t speak at all, and parents discovered they could form complete and complex sentences in emergencies,” illustrates Ostrolenk. For instance, one child was able to explain there was a fire in the kitchen and they needed to leave immediately, despite never having spoken before.

Rethinking Intervention Methods for Autistic Individuals

This study suggests that language acquisition in some autistic individuals might follow an alternative path, possibly indicating new educational paradigms. “In the past, an intense interest in letters was often seen as an obstacle to normal development, and there was a belief that this interest needed to be curtailed to focus on other developmental areas,” Ostrolenk notes. “But if we show that reading can be an essential step in oral language development for these children, then we must encourage this interest and support the child’s unique trajectory.”

“To innovate in the field, we shouldn’t only look at what autistic children don’t do or do differently, but also understand their interests and how they succeed in developing with what is likely a different perception of the world,” concludes Gagnon.