12-18 months: It's About Trust -- Milestones

1. Relies on the presence of familiar adults to try things.

Mobile infants depend on their parents and caregivers to be their base of safety and security. As babies begin to venture out in the world to explore and play, they pause at times to check in for a reassuring touch, word, or smile. In the presence of trusted adults, they feel safe to experiment and to become absorbed in what they're doing. For example:

Developing as expected, they might:

• crawl through the cloth tunnel after they see a trusted face at the other end
• explore and experiment with new materials such as play dough, when the teacher or caregiver is sitting at the table
• continue to stack cardboard blocks after being given a reassuring smile or an encouraging word by a caregiver from across the room
• play on the rocky boat, climb out and go over to the caregiver to touch his or her leg, then return to the rocky boat
• stop playing when a parent leaves the room, but start playing again when the parent returns
• go to get a trusted adult and, with words or gestures, show that they want that person to be near them

Needing development, they might:

• not try crawling through the cloth tunnel even with encouragement
• not let go of their parent's leg the whole time they're in the store
• not let their caregiver get them out of the stroller at the park
• tentatively climb up two steps of the ladder, as long as a familiar person is standing right there and keeps one hand on their leg
• try the swing only if someone familiar holds their hand while they swing

2. Shows awareness of unfamiliar adults.

One-and-a-half-year-olds often appear worried around unfamiliar people. This can seem like a step backward in development if they have previously seemed very secure around all adults. They have learned how important their parents and caregivers are, and now they feel vulnerable around strangers. They show their discomfort in a variety of ways. They can appear to be both curious and cautious at the same time, alternating between approaching and retreating. Babies look to familiar adults for reassurance as they try to figure out what to do. For example:

Developing as expected, they might:

• hide behind their parent, but peek out when a new person their parent has been talking to says hello
• move to the other side of the room when an unfamiliar person enters the room
• cry when their parent leaves them at child care, but slowly settle with the help of the caregiver
• cry when they see a face that is different from what they are used to, such as a clown or someone with a mustache or beard
• allow a stranger to approach them only when the stranger does something familiar, such as wave to them or start a game of peekaboo

Needing development, they might:

• move over without hesitation to the new person and hold out a toy for inspection
• climb into the new person's lap and hold out a book to read
• not respond to a new person even when that new person says hello
• reach to be picked up and hug the new person who has just arrived
• look toward a new person and smile or wave