One of the nine-month-old babies in your infant program has always transitioned easily in the morning. You can tell from several clues that he has recently achieved object permanence. He begins to fuss and cries at separation from his parents in the morning, and they are alarmed at what they see as evidence that he is no longer happy in your program. You are convinced that his recent "clinginess" is related to his development. How can you explain this to the baby's parents?