Eyes wide, a baby reaches for a toy. Her caregiver, sensing her interest, brings the toy within her grasp.

“Ga!” the baby exclaims, and her caregiver responds, “Yes!”

When the baby fusses, her caregiver rubs her back until she calms. The baby smiles, and her caregiver smiles back in a moment of what psychologist Dr Mary Ainsworth (PhD) called “mutual delight.”

This is the dance of an infant and responsive caregiver. These ‘serve-and-return‘ interactions are critical for babies’ development.