Babies smile in their sleep due to active REM sleep, where brain activity causes spontaneous muscle twitches, including smiles, as their nervous system develops, often linked to reflexes or passing gas, rather than complex dreams. These "sleep smiles" are normal and help develop facial muscles, laying the groundwork for later social smiles and emotional expression, with some suggesting they process pleasant sensations or even recall experiences.
Why do babies make an O shape with their mouths? Babies often make an "O" shape with their mouths when they're feeling content and relaxed.
Staring at Lights and Ceilings: Infants often show interest in lights and their surroundings as they begin to explore the world around them. However, excessive fixation on lights or objects could potentially be a sign of sensory processing differences.
It can mean that the baby feels safe and secure and is experiencing positive emotions. Bonding: The angelic smile can have a meaning that goes beyond the purely external. It can symbolize a connection between parents and baby and strengthen a deep bond between them.
In experiments, babies consistently prefer people who help others and avoid those who show anger or harmful behavior. They're not judging “good” or “bad” like adults—but their brains are already wired to sense safety, kindness, and emotional intent.
Theories behind the reasons why babies smile in their sleep
Physical response to pleasant dreams – Some experts believe that newborns smile in their sleep because they are dreaming about pleasant experiences, such as being in the womb or breastfeeding.
Separation anxiety, on the other hand, can cause much longer phases of clinginess. According to the AAP, many children begin having some feelings of separation anxiety around the time they're 8 months old, with the phase peaking between 10 and 18 months and mostly resolving by the time a child turns 2.
Autism in young children
avoiding eye contact. not smiling when you smile at them. getting very upset if they do not like a certain taste, smell or sound. repetitive movements, such as flapping their hands, flicking their fingers or rocking their body.
While it might be difficult to explicitly gauge whether babies feel love when kissed, their responses can be indicative of positive emotional experiences. Often, babies respond to kisses with smiles, coos, or a general sense of contentment, suggesting that their emotional needs are being met.
The first three months with your baby often seem the hardest. Sleep-deprived parents can feel overwhelmed, but that is normal and you will quickly learn how to read your baby's cues and personality. Don't worry about “spoiling” your baby at this stage.
Top Signs Your Baby May Be Gifted
Why Does SIDS Peak at 2-4 Months? The widely accepted explanation for the SIDS peak has to do with the timeline of brain development. “Up to 4 months old, the part of the brain that controls breathing and wakefulness is under a lot of development,” Juliet explains.
Hold your baby until they're in a deeper sleep. Babies start in 'active sleep' (with faster, uneven breathing) and move into a deeper sleep after about 20 minutes. That's a good time to transfer them into their sleeping place. Many babies don't like being put down into a cot.
The Japanese have discovered an ingenious way to put your baby to sleep in exactly 13 minutes. If your baby can't fall asleep, the trick is to hold him in your arms for five minutes while walking and then for another eight minutes.
Around 90% of autism cases are attributed to genetic factors, meaning autism is highly heritable, with many different genes contributing, rather than a single cause, often interacting with environmental influences during early brain development, though specific environmental factors don't cause it but can increase risk. Twin studies show strong genetic links, with concordance rates between 60-90% in identical twins, and research points to complex interactions of many genes and prenatal/perinatal factors.
Reaching to one's own forehead in response to a marked mirror image has traditionally been conceptualized as an important, initial measure of self awareness (the mirror self recognition test, or MSR, e.g. Gallup, 1970) and it typically emerges between the ages of 18 and 24 months (Bertenthal and Fischer, 1978).
Early signs of autism in babies (6 months to one year) may include:
Early findings suggest that having a mother's smell nearby may support sleep regulation and help babies feel more settled. Other work is examining whether items carrying a familiar scent, such as clothing or bedding, can help infants feel comforted and ease the transition from wakefulness to sleep.
The development of self-recognition has been studied mainly by examining infants' responses to their reflections in mirrors. The definitive test is whether or not the infant is capable of using the reflection to notice and respond to a mark on the face or head by touching the mark.
By about 4 to 6 months of age, babies become more social. They love to cuddle and laugh. They become expressive and may "flirt" with their doctor or people across a room. Facial expressions now consistently reflect anger, joy, interest, fear, disgust, or surprise.
In conclusion, babies with autism do smile, though their patterns may differ from neurotypical development. Just like every child's smile is unique, so is their journey—and early support can make a meaningful difference.
0-6 weeks (Reflexive): These are the earliest smiles, the ones you see appear when the baby is getting drowsy, experiencing REM sleep or simply passing gas. Often more of a grimace, these smiles are purely a physical reflex and last no longer than a few seconds.
Infants are at the highest risk for SIDS during their first 6 months of life. Most SIDS deaths occur when babies are between 1 and 4 months of age.