Some scientists believe that infants’ rapid brain growth mirrors the changes that have been shaped over the process of evolution.

Researchers note that babies may cry with the intonations of their mother tongue.

The development of language occurs in four stages: babbling stage, single-word stage, two-word stage, and multi-word stage.

Common causes of social and emotional developmental delays include autism, Asperger syndrome, and childhood disintegrative disorder. Some early signs of autism include lack of eye contact, refusal to cuddle, and apathy toward parents or caregivers.

The most common type of developmental delay in children is language and speech problems. Speech refers to verbal expression, such as the way words are formed. Language is more broad and includes expressing and receiving information, such as understanding gestures.

Trauma or exposure to toxins during the prenatal period can impact later childhood development. Some dangers include prenatal exposure to drugs, toxins, and disease.

At around the 28th week of pregnancy, babies can begin to smell the same smells as their mother. In fact, the amniotic fluid enhances a baby’s smell.

A baby begins to “breathe” at around the 27th week, when its fluid-filled lungs start to expand and compress due to the rhythmic contractions of the mother’s diaphragm and chest muscles.

Babies are born with the ability to taste sweet, bitter, and sour; however, they can’t taste salt until they’re 4 months old, when sodium-sensitive receptor proteins begin to emerge in the taste buds. The development to taste may correspond to the development of the kidneys.

A baby’s eyes are about 75% of adult size, but its vision is blurry at 20/400. A baby’s vision should improve to 20/20 by 6 months old.

About 90% of kids are right handed. There are more lefties in the U.S. than in other cultures, especially in cultures that view left-handedness as taboo.

Children can’t remember much before the age of 3 due to what psychologists call “infantile amnesia.”

Babies see in two dimensions until 2–4 months old. After this, an infant’s cerebral cortex matures enough to merge input from both eyes, which results in 3D vision.

Male babies are born with as much testosterone as a 25-year-old man. After birth, testosterone levels plummet until puberty.

Holding and stroking an infant helps release hormones that are important for its growth.

Just before and after birth, as many as 40,000 new synapses are added every second to a baby’s brain.

A baby’s brain reaches 70% of its adult size by the first birthday and 80% by the second birthday.

Girls who eat regular family meals in a pleasant atmosphere are less likely than average to develop an eating disorder and become overweight.

Preschool children’s ability to resist temptation is a much better predictor of eventual academic success than their IQ scores. Additionally, children who are skilled at behavioral self-control show less anger, fear, and discomfort and higher empathy than their peers who are not.

While playing classical music isn’t likely to help their brain development, having children play or sing the music can increase visual, motor, attention, and mathematical skills.