Development and validation of the Four-Item Mentalising Index

Area of Science:

• Psychology
• Neuroscience
• Social Cognition

Background:

• Mentalising, or Theory of Mind, is crucial for social understanding.
• Existing mentalising measures have limitations, including length and conflation with other constructs.
• These limitations hinder research and clinical applications in social cognition.

Purpose of the Study:

• To develop and validate a brief, reliable self-report measure of mentalising ability.
• To address the methodological and practical limitations of existing mentalising assessment tools.
• To create a scale suitable for large population studies and clinical practice.

Main Methods:

• Development of the Four-Item Mentalising Index (FIMI) based on social cognition questionnaires.
• Factor structure and reliability analyses (Studies 2a and b).
• Validation against cognitive tasks, autistic traits, and group comparisons (Studies 3a and b).

Main Results:

• The FIMI demonstrated sound factor structure and reliability.
• Construct validity was supported through correlations with cognitive tasks and autistic traits.
• The FIMI effectively differentiated between autistic and non-autistic individuals.

Conclusions:

• The FIMI is a conceptually and methodologically robust tool for assessing mentalising ability.
• The scale is suitable for use in the general population, including autistic and non-autistic individuals.
• The FIMI offers practical applications for understanding and managing atypical mentalising.