When are infants first able to use the arms in complementary roles, such as holding a box lid open with one hand while the other removes an object from the box?

the last half of the second year

Explanation:

The last half of the second year in an infant means the last 6 months, between July - December of the year the infant will clock two years. That is the remaining six months preceding his / her two years birthday.

At this time the sensory and motor neurons of the infant has tremendously developed in such a way that he/she has the ability to grasp an object with the use of the arms. Several attempts would have been made before this time, where the infant would have made attempts of grasping objects with one hand.

It Should be understood that, based on the research conducted, it has been discovered that most infants successfully hold or grasp things with their right hand or arm more than the left one.

The last half of the second year

Explanation:

When are infants first able to use the arms in complementary roles, such as holding a box lid open with one hand while the other removes an object from the box?

During the infant and toddler years, children develop basic manipulation skills, their motor skills develop as their whole body starts to move and become more stable, they also learn to do more things with their hands. In infant lifting one's head, rolling over, crawling and siting up are example of development of basic skills. The development of these roles are graded occurring to their age of development. For example an infants is first been visually guided at 4-7 month of age and also able to select a uni-manual reach at the last half of the first year