How does speech and language therapy assess non-verbal communication in autism? 

Non-verbal communication is a core part of how many autistic people express themselves, and UK guidance from NICE, NHS, NAS and the RCSLT describes it as essential to understanding communication strengths and support needs. Speech and language therapists (SLTs) therefore assess non-verbal communication using observation, structured play, AAC assessments and collaboration with families across daily settings. 

Understanding the concept 

Non-verbal communication includes eye gaze, facial expression, gestures, body movements, joint attention, emotional expression and how a person initiates or responds during interactions. According to NICE, social-communication assessments for autistic children and young people must consider these interaction patterns across different settings. 
For adults, NICE highlights the importance of understanding communication style, sensory sensitivities and anxiety, all of which influence non-verbal communication. 

The NHS explains that autistic people may use or interpret non-verbal communication differently. The NAS adds that communication may be multimodal through gestures, behaviour, AAC, pictures or writing and should always be recognised as valid. The RCSLT emphasises that behaviour can be communicative and should be understood within the person’s sensory and emotional context. 

Evidence and impact 

Research describing communication in minimally verbal autistic children shows that joint attention, gesture, coordinated gaze and shared engagement can be reliably assessed through structured play and naturalistic observation, forming the basis of SLT decision-making. In the review of interventions for minimally verbal children, non-verbal communication outcomes such as initiations, gaze shifts and gestures were central to understanding progress. 

Joint-attention intervention studies such as JASP-based research demonstrate that SLTs and multidisciplinary teams can track non-verbal gains using standardised coding of gestures, gaze, and shared attention. 

Evidence for AAC assessments also highlights the importance of analysing gestures, facial expression, intentionality and sensory-motor abilities before choosing a system, reflected in AAC guidance from the RCSLT and AAC systematic reviews 

Practical support and approaches 

SLTs assess non-verbal communication through: 

1. Naturalistic observation 

Aligned with NICE and RCSLT guidance, SLTs observe interactions during play, routines and everyday activities to understand: 

• gaze and attention 

• gestures and pointing 

• facial expression and emotional cues 

• how the person initiates, responds or regulates 

• sensory influences on communication 

NHS services, such as Lincolnshire and Nottinghamshire social-communication pathways, outline this as standard practice in multidisciplinary autism pathways. 

2. Structured interaction tasks 

These include play-based activities to assess: 

• joint attention 

• turn-taking 

• imitation 

• symbolic play 

• non-verbal intentional communication 

Tools often used in practice include SCERTS-informed checklists, pragmatic profiles and joint-engagement coding frameworks. 

3. AAC-focused assessment 

Because AAC is a key part of communication for many autistic people, SLTs review: 

• how the person currently communicates (gesture, vocalisation, body movement) 

• symbol understanding 

• motor and sensory-perceptual skills 

• preferred communication partners 

• emotional regulation in communication 

This mirrors the AAC guidance from the RCSLT. 

Structured frameworks such as the Communication Matrix assess early or non-verbal communication, mapping communicative intent from pre-intentional behaviours to symbolic communication, with strong validity evidence. 

Challenges and considerations 

Assessment must be adapted to the person’s sensory needs, comfort and communication preferences. 

The RCSLT describes the Double Empathy Problem misunderstandings between autistic and non-autistic communicators reminding clinicians to interpret behaviours within the autistic person’s context, not via neurotypical norms. 

The NAS notes that reduced eye contact or atypical gesture does not indicate lack of understanding, so SLTs must avoid pathologising differences. 
Both the NHS and NICE highlight that anxiety and sensory overload can mask communication abilities, requiring flexible assessment formats such as video samples from home or quiet, low-arousal settings. 

How services can help 

SLTs work within NHS, education and community teams to build a holistic communication profile that supports participation, wellbeing and autonomy. Assessments informed by NICE, NAS and the RCSLT ensure that recommendations extend beyond clinic tasks into real-world communication. 

Services may offer: 

• parent-coaching to support non-verbal communication at home 

• AAC trials and selection 

• school-based support for communication-friendly environments 

• multidisciplinary assessment for complex communication needs 

Takeaway 

Speech and language therapy assesses non-verbal communication in autism through careful, respectful observation of how a person expresses themselves, connects with others and navigates their environment. Guided by NICE, NHS, NAS and the RCSLT, SLTs use structured and naturalistic tools including AAC assessments and joint-attention measures to build a communication profile that supports autonomy, participation and wellbeing. 

If you or someone you support would benefit from early identification or structured autism guidance, visit Autism Detect, a UK-based platform offering professional assessment tools and evidence-informed support for autistic individuals and families.