Which is better: A Nanny or a Daycare? For many moms and dads, this is the million-dollar question. Most parents, given the choice, would prefer to have one-on-one care for their child provided by a single, familiar caregiver. But at an average cost of $850 a week (almost $50,000 a year if you factor in a bonus and other benefits) the cost of a nanny represents a significant financial stretch for many people. Daycare naturally costs much less. If you are in a position to afford either option, which one should you choose?

This is one case where the science of child development has a clear answer. During the first six to twelve months of your child’s life, the caregiver-to-child ratio really matters. Babies need a lot of attention in those first early months because they can’t neurologically self-soothe. Babies cannot stop a crying jag that occurs babies want to be held; children with reflux or colic may need extra care. Numerous studies show that infant brain development is highly influenced by the responsiveness of the child’s primary caregiver. Even in the best daycare centers, it can be hard for a baby to get the amount of one-on-one care that they need. In the first year of life outside the womb, your child is learning trust vs. mistrust (“If I cry, will someone respond and make me feel safe?”). They learn how to form secure attachments with others through repeated, positive, loving interactions, such as holding, smiling, singing, and rocking. With a 4:1 ratio in daycare, your baby will without question experience fewer of these interactions than he would with a single, devoted caregiver. Science tells us that 90% of the brain develops by age three, so whatever your child experiences as an infant will become the foundation of his emotional and behavioral makeup later in life.

I often interact with clients who can just barely afford nannies. Hiring one will be a financial stretch, and they wonder if the cost is truly worth it. To these clients I say this: If there is any way that you can stretch and have a nanny for the first 6-12 months of your child’s life, do it. Research supports the incomparable benefits one-on-one care that is provided by a loving caregiver can have on your child’s emotional, social and cognitive development during that time. After the first year, daycare may suffice. It may even have advantages because of the social and educational engagements. During the first few months, however, having someone to focus on your child and respond to her needs consistently, just as a parent would, will make a huge amount of difference.

Nevertheless,Keep in mind that the success of whatever option you choose is not only about the type of care itself, but also about the amount of time and effort you put into finding the very best nanny or daycare for your child. An excellent day care center can outshine a mediocre nanny any day. Quality must always come first.