Do unaffected relatives of autistic individuals show subtle autism traits?

PostedNovember 19, 2025

UpdatedNovember 19, 2025

ByMy Patient Advice

Author: Lucia Alvarez, MSc | Reviewed by: Dr. Rebecca Fernandez, MBBS

Yes, it is common to see autism traits in relatives of autistic individuals, even if those family members do not meet the criteria for a formal diagnosis. These are often referred to as subclinical traits or the broader autism phenotype, and they can include subtle differences in communication, routine preferences, social interaction or sensory sensitivity.

These traits may be mild enough not to cause significant challenges, yet still reflect the same underlying genetic influences that contribute to autism. Relatives who display these characteristics may not have recognised them as part of a wider neurodevelopmental profile, especially if they grew up before autism was widely understood. Understanding the broader phenotype can be valuable for families trying to understand patterns of inheritance, especially when multiple relatives share similar strengths and challenges.

What Subclinical Traits Might Look Like

Here are two common ways autism traits in relatives may appear in daily life:

Mild social and communication differences

Some relatives may prefer solitude, find small talk uncomfortable or struggle with reading social cues. These subclinical traits can be present without causing distress, but they can also help explain family patterns when viewed alongside a formal autism diagnosis in another member.

Rigidity and sensory preferences

Routine-driven behaviour, sensitivity to sound or texture, and intense personal interests are traits sometimes seen in parents or siblings of autistic individuals. These behaviours may reflect the broader phenotype, shaped by shared genetics.

Recognising autism traits in relatives helps families build understanding and fosters a more inclusive view of neurodiversity. Visit providers like Autism Detect for personal consultations and further guidance on screening and support.

For a deeper dive into the science, diagnosis and full treatment landscape, read our complete guide to Genetic Influences.

Lucia Alvarez, MSc

Author

Lucia Alvarez is a clinical psychologist with a Master’s in Clinical Psychology and extensive experience providing evidence-based therapy and psychological assessment to children, adolescents, and adults. Skilled in CBT, DBT, and other therapeutic interventions, she has worked in hospital, community, and residential care settings. Her expertise includes grief counseling, anxiety management, and resilience-building, with a strong focus on creating safe, supportive environments to improve mental well-being.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the author's privacy.

Dr. Rebecca Fernandez, MBBS

Reviewer

Dr. Rebecca Fernandez is a UK-trained physician with an MBBS and experience in general surgery, cardiology, internal medicine, gynecology, intensive care, and emergency medicine. She has managed critically ill patients, stabilised acute trauma cases, and provided comprehensive inpatient and outpatient care. In psychiatry, Dr. Fernandez has worked with psychotic, mood, anxiety, and substance use disorders, applying evidence-based approaches such as CBT, ACT, and mindfulness-based therapies. Her skills span patient assessment, treatment planning, and the integration of digital health solutions to support mental well-being.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the reviewer's privacy.