Wait wait, don't tell me: Handedness questionnaires do not predict hand preference for grasping

Area of Science:

• Psychology
• Neuroscience
• Human Laterality

Background:

• Handedness questionnaires are crucial screening tools in psychology and neuroscience.
• They assess participant laterality when performance may be affected by hand preference.
• Common examples include the Edinburgh Handedness Inventory and Waterloo Handedness Questionnaire.

Purpose of the Study:

• To evaluate the accuracy, reliability, and predictive utility of a combined questionnaire (E-WHQ).
• The E-WHQ integrates 22 questions from established handedness inventories.
• This study specifically tested its ability to predict hand preference for a grasp-to-construct task.

Main Methods:

• Participants completed a 22-item combined questionnaire (E-WHQ) using a five-point scale for hand preference.
• Accuracy was assessed using scrambled versus consistent response keys.
• Test-retest reliability was evaluated by re-administering the inventory.
• Predictive validity was determined by correlating E-WHQ scores with performance on a grasping task.

Main Results:

• Handedness scores decreased by 5% with a scrambled response key, indicating reduced accuracy.
• Test-retest reliability was weak, with 34% of items yielding different responses upon retesting.
• The E-WHQ scores did not correlate with dominant-hand use in a grasping task for either left- or right-handers.

Conclusions:

• The combined Edinburgh-Waterloo Handedness Questionnaire (E-WHQ) demonstrates significant limitations in accuracy and reliability.
• Its responses do not reliably predict hand preference for grasping actions.
• The E-WHQ is deemed unsuitable for predicting hand preference in tasks involving grasping.