Human beings are “wired” for language, and children have an innate ability to master the oral languages around them without any formal lessons from an adult (Pinker, 1994; Kuhl, 2011). Throughout human history, we underestimated what infants can perceive and process in their minds, and wrongly assumed that they cannot understand language at such a young age. Today, we know that language development begins in utero when the auditory system begins to develop first in the brain (Morrongiello, Fenwich, Hillier, & Chance, 1994). A baby picks up on the sounds of human voices while in the mother’s womb and begins to process these voices through their developing auditory system. Upon birth, infants can perceive the familiar voices and turn their heads toward the recognized sounds. In the first two years of development, infants begin to process and make sense of the many sounds of human languages by cataloging these sounds in their minds almost like statistics, and then begin producing first words in later years (Gopnik, Meltzoff, & Kuhl, 1999).

Dr. Patricia Kuhl (2012), who researches early language and brain development, has conducted research on babies as young as a few months old and measured their brain activity using highly sophisticated, precise equipment such as a magnetoencephalography, which measures magnetic fields generated by the activity of brain cells in the baby. Her research investigates how, where, and with what frequency babies from around the world process speech sounds in the brain when they are listening to adults speak in their native versus non-native languages. The conclusion from this seminal research states that babies can perceive all the sounds within human languages until they reach the age of 10 to 12 months, when they begin to focus instead on primarily the immediate sounds in their native tongues. The narrowing of sound/language perception may benefit the child overall as it makes room for other important aspects of development, such as perceiving how objects work or understanding the self and others (Bjorklund & Causey, 2018).