SIAS: Social Interaction Anxiety Scale

What this assessment is

The Social Interaction Anxiety Scale, or SIAS, is a 20-item self-report measure of anxiety during social interaction.

Richard Mattick and Christopher Clarke developed it with the Social Phobia Scale. Their 1998 validation paper treats the two as companion measures with different targets.

The SIAS focuses on meeting, talking with, and responding to other people. It measures severity on a continuous scale and does not diagnose social anxiety disorder.

Its focus is narrow.

Who it was designed for

The original research included people with social phobia, other anxiety conditions, and community participants. Later studies tested the SIAS across clinical, student, community, and translated samples.

These groups do not share one expected score.

Culture, language, age, setting, and administration method can change the distribution. Use norms or decision points only when they come from a population that fits the person being assessed.

This page covers the original 20-item adult form.

Version matters.

How it is administered

The SIAS is usually self-completed. Each statement receives a rating from 0 to 4 based on how characteristic it is of the respondent.

The standard form does not set a recent recall period. It asks about a person's usual experience in social interaction.

Use all 20 items and the standard response scale. Do not add a past-week instruction unless a specific validated adaptation requires it.

Keep it intact.

A 19-item SIAS also appears in research. Short forms with six or 17 items exist as well. Their totals are not interchangeable with the original 20-item score.

The ranges differ.

Name the version.

What it measures

The SIAS measures discomfort and anxiety when interacting with other people. It covers conversation, meeting others, maintaining social contact, and feeling at ease during interaction.

It does not focus mainly on being watched while performing a task. The companion SPS covers scrutiny and observed performance more directly.

The LSAS takes a wider approach. It rates both fear and avoidance across social and performance situations, usually through a clinician interview.

These measures overlap, but they do not produce equivalent scores.

Do not merge them.

How scoring works

Each of the 20 responses scores from 0 to 4. Three positively worded items are reverse scored. Add the corrected values.

The total runs from 0 to 80. Higher scores indicate greater social interaction anxiety.

The reverse-scoring step is required. Skipping it can inflate or distort the total.

An independent validation study confirms the 20-item form, the three reversals, and the 0-to-80 range. It also supports keeping SIAS and SPS as separate totals.

That separation is deliberate.

Do not combine them into a 0-to-160 score unless a research protocol explicitly defines and supports that analysis.

How to interpret a SIAS score

Interpret the SIAS as a continuous measure. A higher total means that the respondent reports more anxiety or discomfort during social interaction.

Research has used decision points for particular clinical comparisons. Those figures vary by sample, language, and purpose. They are not universal severity bands.

Avoid fixed online labels.

Context comes first.

Review the total with the situations that cause difficulty, the amount of avoidance, and the effect on daily life. For repeated measurement, keep the version, language, and administration method the same.

What the score cannot tell you

The SIAS cannot confirm social anxiety disorder. It cannot show whether interaction difficulty comes from trauma, depression, autism, communication differences, discrimination, limited opportunity, or another cause.

It does not give a full measure of performance fears or avoidance. It also does not assess immediate safety.

Do not diagnose from the total.

That is the limit.

A low score can coexist with one severe social fear. A high score does not explain the source of the anxiety or select a treatment.

One total cannot explain cause.

Evidence and limitations

The original study found strong reliability and expected differences between social-phobia and comparison groups. Later work has supported the scale across several languages and settings.

The positively worded items can behave differently from the other items. Some researchers remove one or more of them, which is one reason 19-item and short forms exist.

That creates a version problem. Confirm the item count and range before using a published mean, cutoff, or change estimate. A score from a modified SIAS should not be presented as the standard 20-item result.

That limit is firm.