Brith 1 month they show a basic attraction to people
At 2 months they show primary intersubjectivty which means they have the ability to share emotions experinces and intetions with other
At 5 months they show topic based relatedness involves infants moving from one-on-one interactions to including more things that interest them
At 9 to ten months they show secondary inter subjcetivty which means infant development that involves sharingattention with a caregiver to explore the world around them
And at 18 months they devlop Cooperative relatedness infants which means they can now engage in and respond to interactions that involve mutual goals
Babies are born socially ready so they are biologically designed to look helpless and activate caring behaviour in parents.
Specific responses to babyfaces motivate caretaking behaviour