Edinburgh Handedness Inventory - Short Form: a revised version based on confirmatory factor analysis

Area of Science:

• Psychology
• Neuroscience
• Human Behavior

Background:

• The Edinburgh Handedness Inventory (EHI) is widely used but lacks sufficient factorial validity studies.
• Concerns exist regarding the EHI's original instructions and response options, potentially confusing participants.
• Previous modifications, including a 7-item version, have also shown model misspecification.

Purpose of the Study:

• To assess the factorial validity of the Edinburgh Handedness Inventory.
• To develop and validate a brief, reliable, and user-friendly short form of the EHI.
• To evaluate the psychometric properties and factorial invariance of the proposed short form.

Main Methods:

• Administered a simplified Edinburgh Handedness Inventory to 1514 participants via an online questionnaire.
• Utilized confirmatory factor analysis to assess model fit for the original 10-item EHI and a proposed 7-item modification.
• Developed and validated a 4-item Edinburgh Handedness Inventory - Short Form, examining its reliability and factorial invariance.

Main Results:

• The original 10-item EHI model demonstrated poor data fit, consistent with prior research.
• A previously proposed 7-item modification also exhibited model misspecification.
• The newly developed 4-item Edinburgh Handedness Inventory - Short Form showed good model fit, high reliability, and strong correlation with the 10-item version.
• Factorial invariance was established across education levels, age groups, regions, and generally across genders.

Conclusions:

• The 4-item Edinburgh Handedness Inventory - Short Form is a psychometrically sound instrument for measuring a single handedness factor.
• The short form provides a brief, easily understandable, and reliable alternative to the original EHI.
• This validated short form addresses concerns about over-categorizing mixed handers and offers robust factorial invariance.