Child development refers to the process in which children go through changes in skill development during predictable time periods, called developmental milestones. Developmental delay occurs when children have not reached these milestones by the expected time period. For example, if the normal range for learning to walk is between 9 and 15 months, and a 20-month-old child has still not begun walking, this would be considered a developmental delay.
Developmental delays can occur in all five areas of development or may just happen in one or more of those areas .Additionally, growth in each area of development is related to growth in the other areas. So if there is a difficulty in one area (e.g., speech and language), it is likely to influence development in other areas (e.g., social and emotional).
As a child grows and develops, he learns different skills, such as taking a first step, smiling for the first time, or waving goodbye. These skills are known as developmental milestones. There is normal variation around what age children will achieve a specific developmental milestone. Developmental delay refers to a child who is not achieving milestones within the age range of that normal variability. Most often, at least initially, it is difficult or impossible to determine whether the delay is a marker of a long-term issue with development or learning (i.e. known as a disability) or whether the child will ‘catch-up’ and be ‘typical’ in their development and learning. ’There are five main groups of skills that make up the developmental milestones. A child may have a developmental delay in one or more of these areas:
- Gross motor: using large groups of muscles to sit, stand, walk, run, etc., keeping balance and changing positions.
- Fine motor: using hands and fingers to be able to eat, draw, dress, play, write and do many other things.
- Language: speaking, using body language and gestures, communicating and understanding what others say.
- Cognitive: Thinking skills including learning, understanding, problem-solving, reasoning and remembering.
- Social: Interacting with others, having relationships with family, friends, and teachers, cooperating and responding to the feelings of others.
Usually, there is an age range of several months where a child is expected to learn these new skills. If the normal age range for walking is 9 to 15 months, and a child still isn’t walking by 20 months, this would be considered a developmental delay (2 standard deviations below the mean). A delay in one area of development may be accompanied by a delay in another area. For example, if there is a difficulty in speech and language, a delay in other areas such as social or cognitive development may coexist.
It is important to identify developmental delays early so that treatment can minimize the effects of the problem.
Risk factors for developmental problems fall into two categories:
Children are placed at genetic risk by being born with a genetic or chromosomal abnormality. A good example of a genetic risk is Down syndrome, a disorder that causes developmental delay because of an abnormal chromosome.
Environmental risk results from exposure to harmful agents either before or after birth, and can include things like poor maternal nutrition or exposure to toxins (e.g. lead or drugs) or infections that are passed from a mother to her baby during pregnancy (e.g., measles or HIV). Environmental risk also includes a child’s life experiences. For example, children who are born prematurely, face severe poverty, mother’s depression, poor nutrition, or lack of care are at increased risk for developmental delays.
Risk factors have a cumulative impact upon development. As the number of risk factors increases, a child is put at greater risk for developmental delay.
There are several general “warning signs” of possible delay. These include:
- Behavioral Warning Signs
- Does not pay attention or stay focused on an activity for as long a time as other children of the same age
- Focuses on unusual objects for long periods of time; enjoys this more than interacting with others
- Avoids or rarely makes eye contact with others
- Gets unusually frustrated when trying to do simple tasks that most children of the same age can do
- Shows aggressive behaviors and acting out and appears to be very stubborn compared with other children
- Displays violent behaviors on a daily basis
- Stares into space, rocks body, or talks to self more often than other children of the same age
- Does not seek love and approval from a caregiver or parent
- Gross Motor Warning Signs
- Has stiff arms and/or legs
- Has a floppy or limp body posture compared to other children of the same age
- Uses one side of body more than the other
- Has a very clumsy manner compared with other children of the same age
- Vision Warning Signs
- Seems to have difficulty following objects or people with her eyes
- Rubs eyes frequently
- Turns, tilts or holds head in a strained or unusual position when trying to look at an object
- Seems to have difficulty finding or picking up small objects dropped on the floor (after the age of 12 months)
- Has difficulty focusing or making eye contact
- Closes one eye when trying to look at distant objects
- Eyes appear to be crossed or turned
- Brings objects too close to eyes to see
- One or both eyes appear abnormal in size or coloring
- Hearing Warning Signs
- Talks in a very loud or very soft voice
- Seems to have difficulty responding when called from across the room, even when it is for something interesting
- Turns body so that the same ear is always turned toward sound
- Has difficulty understanding what has been said or following directions after once she has turned 3 years of age
- Doesn’t startle to loud noises
- Ears appear small or deformed
- Fails to develop sounds or words that would be appropriate at her age