• The Complete Guidelines
  • Tip Sheet

9 to 18 MONTHS

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.

  • Perceptual Development: The developing ability to become aware of the social and physical environment through the senses.
  • Use the information received from the senses to change the way they interact with the environment.
  • Gross Motor: The developing ability to move the large muscles.
  • Move from one place to another by walking and running with basic control and coordination.
  • Fine Motor: The developing ability to move the small muscles.
  • Hold small objects in one hand and sometimes use both hands together to manipulate objects.
  • Health: Maintenance of healthy growth and participation in physical activity.
  • Demonstrate the stamina and energy to participate in daily activities.
  • Show characteristics of healthy development and maintain growth.
  • Interaction with Adults: The developing ability to respond to and engage with adults.
  • Participate in routines and games that involve complex back-and-forth interaction.
  • Follow the gaze of an adult to an object or person.
  • Check with a familiar adult when uncertain about something or someone.
  • Interaction with Peers: The developing ability to respond to and engage with other children.
  • Engage in simple back-and-forth interactions with peers for short periods of time.
  • Relationship with Peers: The development of relationships with certain peers through interactions over time.
  • Prefer to interact with one or two familiar children in the group and usually engage in the same kind of back-and-forth play when interacting with those children.
  • Empathy: The developing ability to share in the emotional experiences of others.
  • Change their behavior in response to the feelings of others even though their actions may not always make the other person feel better.
  • Show an increased understanding of the reason for another's distress and may become distressed by the other's distress.
  • Social Understanding: The developing understanding of the responses, communication, emotional expressions, and actions of other people.
  • Know how to get adults to respond in a specific way through gestures, vocalizations, and shared attention.
  • Use another's emotional expressions to guide their own responses to unfamiliar events.
  • Learn more complex behavior through imitation.
  • Engage in more complex social interactions and have developed expectations for a greater number of familiar people.
  • Relationships with Adults: The development of close relationships with certain adults who provide consistent nurturance.
  • Feel secure exploring the environment in the presence of important adults with whom they have developed a relationship over an extended period of time.
  • When distressed, seek to be physically close to familiar adults.
  • Identity of Self in Relation to Others: The developing concept that the child is an individual operating with social relationships.
  • Demonstrate awareness of their characteristics and express themselves as distinct persons with thoughts and feelings.
  • Demonstrate expectations of others' behaviors, responses, and characteristics on the basis of previous experiences with them.
  • Recognition of Ability: The developing understanding that the child can take action to influence the environment.
  • Experiment with different ways of making things happen.
  • Persist in trying to do things even when faced with difficulty.
  • Show a sense of satisfaction with what they can do.
  • Expression of Emotion: The developing ability to express a variety of feelings through facial expressions, movements, gestures, sounds, or words.
  • Express emotions in a clear and intentional way.
  • Begin to express some complex emotions, such as pride.
  • Emotion Regulation: The developing ability to manage emotional responses, with assistance from others and independently.
  • Demonstrate a variety of responses to comfort themselves and actively avoid or ignore situations that cause discomfort.
  • Communicate needs and wants through the use of a few words and gestures.
  • Impulse Control: The developing ability to wait for needs to be met, to inhibit potentially hurtful behavior, and to act according to social expectations, including safety rules.
  • Respond positively to choices and limits set by an adult to help control their behavior.
  • Receptive Language: The developing ability to understand words and increasingly complex utterances.
  • Show understanding of one-step requests that have to do with the current situation.
  • Expressive Language: The developing ability to produce the sounds of language and use vocabulary and increasingly complex utterances.
  • Say a few words and use conventional gestures to tell others about their needs, wants, and interests.
  • Communication Skills and Knowledge: The developing ability to communicate nonverbally and verbally.
  • Use conventional gestures and words to communicate meaning in short back-and-forth interactions.
  • Use the basic rules of conversational turn-taking when communicating.
  • Interest in Print: The developing interest in engaging with print in books and the environment.
  • Listen to the adult and participate while being read to by pointing, turning pages, or making one- or two-word comments.
  • Actively notice print in the environment.
  • Cause-and-Effect: The developing understanding that one event brings about another.
  • Combine simple actions to cause things to happen.
  • Change the way they interact with objects and people in order to see how it changes the outcome.
  • Spatial Relationships: The developing understanding of how things move and fit in space.
  • Use trial and error to discover how things move and fit in space.
  • Imitation: The developing ability to mirror, repeat, and practice the actions of others, either immediately or later.
  • Imitate others' actions that have more than one step.
  • Imitate simple actions that they have observed others doing at an earlier time.
  • Number Sense: The developing understanding of number and quantity.
  • Demonstrate understanding that there are different amounts of things.
  • Classification: The developing ability to group, sort, categorize, connect, and have expectations of objects and people according to their attributes.
  • Show awareness when objects are in some way connected to each other.
  • Match two objects that are the same, and separate a pile of objects into two groups based on one characteristic.
  • Symbolic Play: The developing ability to use actions, objects, or ideas to represent other actions, objects, or ideas.
  • Use one object to represent another object.
  • Engage in one or two simple actions of pretend play.
  • Routines: The developing ability to understand and participate in personal care and sleep routines.
  • Show awareness of familiar personal care routines and participate in the steps of these routines.
  • Problem Solving: The developing ability to engage in a purposeful effort to reach a goal or figure out how something works.
  • Physically try out possible solutions before finding one that works.
  • Use objects as tools.
  • Watch someone else solve the problem and then apply the same solution.
  • Gesture or vocalize to someone else for help.
  • Memory: The developing ability to store and later retrieve information about past experiences.
  • Remember typical actions of people, the location of objects, and steps of routines.
  • Attention Maintenance: The developing ability to attend to people and things while interacting with others and exploring the environment and play materials.
  • Rely on order and predictability in the environment to help organize their thoughts and focus attention.
 

Note: It is important to arrange for regular health and developmental exams with a health care provider. These are usually part of a well-child visit and can include vision, hearing and oral health screenings.

Questions? Concerns?

The Guidelines describe how a typical child develops but it is important to understand that each child learns and develops at his or her own individual pace. Since each child is different, caregivers should talk with a health care provider or other trusted professional about any questions or concerns. For more information about questions or concerns you may have, please contact us.