|Onset of bimanual coordination and symmetry versus asymmetry of movement.
49 infants (aged 7-24 mo) were presented with 4 objects requiring different kinds of manipulation. Bimanual manipulations that could be performed with symmetrical movements were successful earlier than manipulations requiring asymmetrical movements. A right-handed pattern for bimanual coordination (left hand holding/right hand active) was observed as early as bimanual manipulation itself--as of 10 months of age. (PsycINFO Database Record (c) 2007 APA, all rights reserved)