Dr. T. Berry Brazelton is the world’s most prominent pediatrician. For six decades, he’s honed his expertise of child development and now at age 89, he’s as vital and relevant as ever.

Dr. Brazelton has just revised his landmark book, a parenting classic called “Touchpoints: Birth To Three.” He tells Growing Bolder why grandparents are so important to children and the most important thing a parent can do to raise a healthy, happy child.

And what is a touchpoint? Dr. Brazelton explains how it has guided a generation of parents and what has changed in the last 50 years.