Everyone loves the toothless grins that newborns flash their way. Although these smiles are absolutely precious, they are completely random and not associated with actual happiness and enjoyment. They are simply triggered by the firing of neurons in the stem of the brain. The twitchy grins occur more often when the infant is sleeping, which scientists believe is due to the fact that the required motor cells are located in the area of the brain stem where REM sleep occurs.
Perma-Grin
Smiling has been proven to not only be enjoyable but also an evolutionary method by which humans are drawn together. Human infants, unlike other species, require constant devoted attention from their caregivers with bonding behaviors being integral to their biological makeup. These adorable smiles are involuntary and are an intrinsic part of building parent-child relationships.
The Real Deal
A genuine smile will not appear on the face of a baby until he or she is a couple of months old. This milestone indicates a maturing of the limbic system, which is the emotional center of the brain. Between four to ten weeks of age, the limbic system and motor systems are mature enough to allow the baby to smile deliberately, and this usually coincides with interested eye contact with mommy.
In all cultures and environments, social smiles occur at the same time, even in babies who are blind. Instead of sights, they react positively to sounds such as the sound of their parents’ voices as well as the touch of their parents’ hands.
The first smile usually causes mommy’s heart to leap into her throat and initiates an onslaught of joyful tears and profuse Facebooking.
The precious first smile of a baby is the primary way in which parents first experience back-and-forth interactions with their offspring. Many psychologists believe that young children display attachment to their parents by saving their genuine smiles for their parents with strangers getting contrived, forced smiles similar to the baby’s earliest grins.
It has been shown that a child’s smile triggers the reward centers in the parent’s brain, which include the striatum, the substantia nigra, and the emotional network situated in the frontal lobes of the brain. These areas utilize dopamine, a neurotransmitter responsible for mood boosts.

