Noah is a 4-month-old infant who prefers to be left alone in his crib, has poor muscle tone, and can spend long periods of time staring at the ceiling fan in his room. This pattern of behavior could be signs of disinhibited social engagement disorder.

In psychology, the term Disinhibited social engagement disorder refers to a attachment disorder. According to the DSM-V, the criteria for this disorder is:

Intense excitement over meeting or interacting with strangers or unfamiliar adults. In other words, they like to interact with strangers but in an exaggerated manner
They are extremely friendly with strangers, they can talk to much to them.
And they could also be willing to leave a place with a stranger.

This is a dangerous situation because these kids put themselves in danger by doing this because they are willing to go with people they don't know. Children with this disorder usually have a caregiver that didn't pay much attention to them and failed to create a secure attachment.

In this example Noah prefers to be left alone in his crib and spends long periods of time staring at the ceiling fan. He is not interacting with strangers at all so this pattern of behavior can NOT be a sign of disinhibited social engagement disorder.