When we think about becoming detectives (or remaining detectives for longer than we think we should have to) in order to understand and meet our children's needs, we can look at their needs as fitting into one of two categories. First, to prevent or interrupt their experience of feeling overwhelmed. Second, to prevent or interrupt their experience of feeling alone and vulnerable.
When parents respond to their infants needs with "just right" care delivered "just in time", they interrupt their children's experience of distress (they 'regulate' them). This decreases the feeling of overwhelm and offers connection. It's the "just right" balance.
Let's think about the diaper change. A dirty diaper presents the child with an overwhelming sensory discomfort that must be eliminated and a desperate need for the caregiver to be present and offer comfort. When the diaper is changed, the experience of overwhelm is eliminated and the caregiver is seen to be loving - reliable, trustworthy and capable; a "safe" person in the child's eyes.
Same thing when a parent responds to a hungry infant. Or a tired one. Or a bored one. Or a lonely one....
When we accurately understand and meet a child's need (whether or not they can verbally state them), we have the ability to "regulate" their distress while nurturing our bond with them.
How do you know what your children need? How do they communicate those needs when they don't use their words?