• Reaching across the body into contralateral space with one hand incurs a substantial cost on various measures of performance, compared to ipsilateral reaches of a similar amplitude (Carey, Hargreaves, \u26 Goodale, 1996).• When reaching with both hands, unimanual asymmetries disappear.-The hands take off and land concurrently (Kelso, Southard, \u26 Goodman, 1979).• To test if this ‘yoking’ is driven by the left or the right hand, participants performed reaches of different amplitudes.• These reaches were made to the left or right side of space.-Further increasing the unimanual (baseline) asymmetries that get wiped out by the yoking.• The hand which is less affected by the other’s presence is likely to be driving the coupling.• The strongest conclusions could be drawn from a relative improvement of a contralateral reaching hand, by the presence of an ipsilateral reaching counterpart.
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