The study looked at how babies learn to use their hands differently when playing with toys. They found that as babies get older, they use both hands in more complex ways. Most babies prefer using their right hand for these tasks, but some prefer their left hand or have no preference. The researchers studied 90 babies and saw that hand preferences for these tasks become stronger as babies grow older. Right-handed babies and those with no preference tend to use their right hand more, while left-handed babies show more variety in hand use.