According to Dr. Jill Stamm, co-founder of the New Directions Institute for Infant Brain Development (NDI) in Arizona, neuroscientific research shows that a baby's brain develops the majority of its synaptic connections and becomes "wired" in the first three years as follows:

Year   Percent of brain wired

1        25%

2        75%

3        90%

Intellectual capacity is therefore NOT fixed at birth since the majority of the wiring comes AFTER birth. That is, intellectual capacity is NOT predetermined. Ages 0 to 3 is the crucial window when the brain is most malleable that parents and caregivers can do what they can to help create maximum synaptic density. 

At the Early Learning Community Lecture hosted by the University of Denver's Marsico Institute for Early Learning and Literacy on April 29, 2010, Dr. Jill Stamm noted that parents can have a "Well-Wired Baby" with a healthy brain by focusing on the "ABC's of Early Learning: Attention, Bonding, Communication." More specifically, parents need to talk, read, sing, play, touch and cuddle with their baby. For example, in order to acquire language, an infant needs eye contact and facetime since an infant's eyes will focus specifically on your mouth, lips, and teeth to learn both the audio and visual cues for language acquisition. Dr. Stamm further noted that there is a linear relationship between the amount of baby-directed talk that an infant receives and their IQ level.