Older infants are ready to explore their world and are becoming more adventurous as their increasing mobility allows them to have new experiences. They are very curious and will actively investigate objects and people in their environment, while still needing the security that familiar adults provide. Older infants show strong attachment to the adults in their life and a fascination with their peers. They practice communication by babbling, and they understand and can respond to a growing number of words.

For some specific examples of these indicators within each domain and what you can do to support children, visit the Parents & Caregivers section for 9-18 months.

Download the Guidelines for children 9-18 months for complete descriptions of specific behaviors and suggested supports.