What is an important developmental milestone for infants by the age of seven months?

The development of object permanence is indeed a significant milestone for infants around the age of seven months. Object permanence refers to the understanding that objects continue to exist even when they cannot be seen, heard, or touched. This cognitive skill is crucial as it lays the foundation for further cognitive development and affects how infants interact with their environment.

When infants begin to grasp this concept, they demonstrate curiosity and exploratory behavior, which are vital for their learning and development. For instance, if a toy is hidden under a blanket, a child with object permanence will search for it, whereas a child without this understanding may not seek it out.

This milestone typically occurs in the latter half of the first year of life, aligning with the developmental progression of cognitive skills. Recognizing faces, while significant, is generally developed earlier and relates more to social-emotional development than cognitive reasoning. Similarly, learning to crawl and expressing basic emotions are important physical and emotional milestones, respectively, but these happen within different timelines and contexts concerning cognitive development.