Early childhood development encompasses the period when children are from one to four years old. Huge changes also take place during this stage, as children change from tiny, dependent infants to children who can walk, talk and begin formal learning. Many of the changes associated with this stage involve movement (walking) and communication (talking). Most children learn to walk early in their second year of life. At such a time, greater vigilance is needed to care for them because they have the ability to reach more dangerous objects, but not the understanding to avoid them.

Communication also grows rapidly in early childhood. Children learn to speak in sentences and understand what is being said to them. The vocabulary grows to about 1,500 words by age four, and children learn some complexities of speech, such as the use of pronouns or the past tense. Likewise, they may use their newfound abilities to test their boundaries in the home. Toddlers learn to say “no” and may refuse to obey their parents or caregivers. Temper tantrums may begin during this period. As children grow toward school age, the likelihood of temper tantrums lessens.

Children also learn to control their bodies during this stage. Most children begin toilet training somewhere before or near their third birthdays. The range differs for each child, but girls can usually be toilet trained earlier than boys. Almost all children have complete bowel and bladder control by the time they reach school age, although some children may have bedwetting problems.

Developmental delays and other problems may become more obvious during early childhood. Learning disabilities may become noticeable if a child does not take an interest in learning and getting ready to read. Other developmental disorders such as Asperger’s syndrome and autism may also become evident if children have problems with communication, social interaction and behavior. Monitoring a child’s development can help parents identify problems early and begin treating them early.

Middle childhood is the developmental period when children are ages five to 10 years old. During these years, children are more independent and physically active than they were during early childhood development. Physical changes mostly relate to growth in height and weight. Loss of primary teeth and the growth of permanent teeth also occur in these years.

Formal education begins during these years and cognitive development continues with greater inputs from reading and learning. The fine motor skills improve in most children with a better ability to write. Learning problems that may not have been identified earlier may become more apparent in these middle childhood years. These include dyslexia and attention deficit hyperactivity disorder (ADHD).