Handedness between bodies: toward a relational account of manual laterality.

Papadatou-Pastou and colleagues' rapid review maps 47 named tasks comparing the relative skill of the two hands. From a relational perspective, most tasks assess a person acting alone. This provides a baseline, but not a complete account of how manual asymmetry is expressed. Evidence that hand choice and attributed handedness vary with target animacy, communicative purpose, partner role, emotional context, or viewpoint raises a further question: can relative hand performance also change when the same or a matched action is embedded in a social context? We use relational handedness to denote systematic variation in hand choice or relative hand performance generated or modulated by an actor's relation to a partner or observer, given a social goal and spatial arrangement. Attributed handedness addresses the neighboring question of how the observer-agent relation shapes perceived manual laterality and helps identify relational variables to manipulate. Relational handedness is not a third score alongside preference and skill, but a testing condition potentially assessing their contextual stability. Future batteries could pair validated individual tasks with matched social and nonsocial conditions and test the hand-by-condition interaction. This would preserve the distinction between preference and skill while separating task noise from meaningful relational modulation.