What is the typical age at which an infant shows no head lag when lifted?

The correct choice indicates that by approximately 4 months of age, an infant typically demonstrates no head lag when lifted. This milestone illustrates the development of neck and head control, which is crucial for the progression of motor skills. At this age, infants begin to strengthen the muscles in their neck and head, allowing them to maintain a more upright position when being held.

By 4 months, most infants can also support their head in a straight line with the body and actively engage in looking around. This control marks an important transition in their physical development, as it lays the groundwork for further milestones such as rolling over and sitting up.

In contrast, younger infants around 2 months tend to show significant head lag when lifted, as they are still developing the necessary muscle strength and coordination. By 6 and 8 months, most infants typically demonstrate advanced motor skills, such as sitting independently, and would have long surpassed the absence of head lag. However, the typical age for achieving no head lag is clearly established around the 4-month mark.