The hallmark feature of autism is impaired social interaction. Children with autism may fail to respond to their names and often avoid looking at other people. They often have difficulty interpreting tone of voice or facial expressions and do not respond to others' emotions or watch other people's faces for cues about appropriate behavior. They appear unaware of others' feelings toward them and of the negative impact of their behavior on other people.
Many children with autism engage in repetitive movements such as rocking and hair twirling, or in self-injurious behavior such as biting or head-banging. They also tend to start speaking later than other children and may refer to themselves by name instead of "I" or "me." Some speak in a sing-song voice about a narrow range of favorite topics, with little regard for the interests of the person to whom they are speaking.
People with autism often have abnormal responses to sounds, touch, or other sensory stimulation. Many show reduced sensitivity to pain. They also may be extraordinarily sensitive to other sensations. These unusual sensitivities may contribute to behavioral symptoms such as resistance to being cuddled. (Source: excerpt from Autism Fact Sheet: NINDS)
People with classical autism show three types of symptoms: impaired social interaction, problems with verbal and nonverbal communication, and unusual or severely limited activities and interests. These symptoms can vary in severity. In addition, people with autism often have abnormal responses to sounds, touch, or other sensory stimulation. Symptoms usually appear during the first three years of childhood and continue through life. (Source: excerpt from NINDS Autism Information Page: NINDS)
People with autism represent a broad spectrum of impairment, with great variability in clinical symptoms and levels of functioning. Some people with autism have normal intelligence and develop good basic language skills, while others lag intellectually and develop little or no language. (Source: excerpt from Autism Research: NIMH)
Children with autism do not follow the typical patterns of child development. In some children, hints of future problems may be apparent from birth. In most cases, the problems become more noticeable as the child slips farther behind other children the same age. Other children start off well enough. But between 18 and 36 months old, they suddenly reject people, act strangely, and lose language and social skills they had already acquired. (Source: excerpt from Autism: NIMH)
From the start, most infants are social beings. Early in life, they gaze at people, turn toward voices, endearingly grasp a finger, and even smile.
In contrast, most children with autism seem to have tremendous difficulty learning to engage in the give-and-take of everyday human interaction. Even in the first few months of life, many do not interact and they avoid eye contact. They seem to prefer being alone. They may resist attention and affection or passively accept hugs and cuddling. Later, they seldom seek comfort or respond to anger or affection. Unlike other children, they rarely become upset when the parent leaves or show pleasure when the parent returns. Parents who looked forward to the joys of cuddling, teaching, and playing with their child may feel crushed by this lack of response.
Children with autism also take longer to learn to interpret what others are thinking and feeling. Subtle social cues-whether a smile, a wink, or a grimace-may have little meaning. To a child who misses these cues, "Come here," always means the same thing, whether the speaker is smiling and extending her arms for a hug or squinting and planting her fists on her hips. Without the ability to interpret gestures and facial expressions, the social world may seem bewildering.
To compound the problem, people with autism have problems seeing things from another person's perspective. Most 5-year-olds understand that other people have different information, feelings, and goals than they have. A person with autism may lack such understanding. This inability leaves them unable to predict or understand other people's actions.
Some people with autism also tend to be physically aggressive at times, making social relationships still more difficult. Some lose control, particularly when they're in a strange or overwhelming environment, or when angry and frustrated. They are capable at times of breaking things, attacking others, or harming themselves. Alan, for example, may fall into a rage, biting and kicking when he is frustrated or angry. Paul, when tense or overwhelmed, may break a window or throw things. Others are self-destructive, banging their heads, pulling their hair, or biting their arms. (Source: excerpt from Autism: NIMH)
By age 3, most children have passed several predictable milestones on the path to learning language. One of the earliest is babbling. By the first birthday, a typical toddler says words, turns when he hears his name, points when he wants a toy, and when offered something distasteful, makes it very clear that his answer is no. By age 2, most children begin to put together sentences like "See doggie," or "More cookie," and can follow simple directions.
Research shows that about half of the children diagnosed with autism remain mute throughout their lives. Some infants who later show signs of autism do coo and babble during the first 6 months of life. But they soon stop. Although they may learn to communicate using sign language or special electronic equipment, they may never speak. Others may be delayed, developing language as late as age 5 to 8.
Those who do speak often use language in unusual ways. Some seem unable to combine words into meaningful sentences. Some speak only single words. Others repeat the same phrase no matter what the situation.
Some children with autism are only able to parrot what they hear, a condition called echolalia. Without persistent training, echoing other people's phrases may be the only language that people with autism ever acquire. What they repeat might be a question they were just asked, or an advertisement on television. Or out of the blue, a child may shout, "Stay on your own side of the road!"-something he heard his father say weeks before. Although children without autism go through a stage where they repeat what they hear, it normally passes by the time they are 3.
People with autism also tend to confuse pronouns. They fail to grasp that words like "my," "I," and "you," change meaning depending on who is speaking. When Alan's teacher asks, "What is my name?" he answers, "My name is Alan."
Some children say the same phrase in a variety of different situations. One child, for example, says "Get in the car," at random times throughout the day. While on the surface, her statement seems bizarre, there may be a meaningful pattern in what the child says. The child may be saying, "Get in the car," whenever she wants to go outdoors. In her own mind, she's associated "Get in the car," with leaving the house. Another child, who says "Milk and cookies" whenever he is pleased, may be associating his good feelings around this treat with other things that give him pleasure.
It can be equally difficult to understand the body language of a person with autism. Most of us smile when we talk about things we enjoy, or shrug when we can't answer a question. But for children with autism, facial expressions, movements, and gestures rarely match what they are saying. Their tone of voice also fails to reflect their feelings. A high-pitched, sing-song, or flat, robot-like voice is common.
Without meaningful gestures or the language to ask for things, people with autism are at a loss to let others know what they need. As a result, children with autism may simply scream or grab what they want. Temple Grandin, an exceptional woman with autism who has written two books about her disorder, admits, "Not being able to speak was utter frustration. Screaming was the only way I could communicate." Often she would logically think to herself, "I am going to scream now because I want to tell somebody I don't want to do something." Until they are taught better means of expressing their needs, people with autism do whatever they can to get through to others. (Source: excerpt from Autism: NIMH)
Although children with autism usually appear physically normal and have good muscle control, odd repetitive motions may set them off from other children. A child might spend hours repeatedly flicking or flapping her fingers or rocking back and forth. Many flail their arms or walk on their toes. Some suddenly freeze in position. Experts call such behaviors stereotypies or self-stimulation.
Some people with autism also tend to repeat certain actions over and over. A child might spend hours lining up pretzel sticks. Or, like Alan, run from room to room turning lights on and off.
Some children with autism develop troublesome fixations with specific objects, which can lead to unhealthy or dangerous behaviors. For example, one child insists on carrying feces from the bathroom into her classroom. Other behaviors are simply startling, humorous, or embarrassing to those around them. One girl, obsessed with digital watches, grabs the arms of strangers to look at their wrists.
For unexplained reasons, people with autism demand consistency in their environment. Many insist on eating the same foods, at the same time, sitting at precisely the same place at the table every day. They may get furious if a picture is tilted on the wall, or wildly upset if their toothbrush has been moved even slightly. A minor change in their routine, like taking a different route to school, may be tremendously upsetting.
Scientists are exploring several possible explanations for such repetitive, obsessive behavior. Perhaps the order and sameness lends some stability in a world of sensory confusion. Perhaps focused behaviors help them to block out painful stimuli. Yet another theory is that these behaviors are linked to the senses that work well or poorly. A child who sniffs everything in sight may be using a stable sense of smell to explore his environment. Or perhaps the reverse is true: he may be trying to stimulate a sense that is dim.
Imaginative play, too, is limited by these repetitive behaviors and obsessions. Most children, as early as age 2, use their imagination to pretend. They create new uses for an object, perhaps using a bowl for a hat. Or they pretend to be someone else, like a mother cooking dinner for her "family" of dolls. In contrast, children with autism rarely pretend. Rather than rocking a doll or rolling a toy car, they may simply hold it, smell it, or spin it for hours on end. (Source: excerpt from Autism: NIMH)
When children's perceptions are accurate, they can learn from what they see, feel, or hear. On the other hand, if sensory information is faulty or if the input from the various senses fails to merge into a coherent picture, the child's experiences of the world can be confusing. People with autism seem to have one or both of these problems. There may be problems in the sensory signals that reach the brain or in the integration of the sensory signals-and quite possibly, both.
Apparently, as a result of a brain malfunction, many children with autism are highly attuned or even painfully sensitive to certain sounds, textures, tastes, and smells. Some children find the feel of clothes touching their skin so disturbing that they can't focus on anything else. For others, a gentle hug may be overwhelming. Some children cover their ears and scream at the sound of a vacuum cleaner, a distant airplane, a telephone ring, or even the wind. Temple Grandin says, "It was like having a hearing aid that picks up everything, with the volume control stuck on super loud." Because any noise was so painful, she often chose to withdraw and tuned out sounds to the point of seeming deaf.
In autism, the brain also seems unable to balance the senses appropriately. Some children with autism seem oblivious to extreme cold or pain, but react hysterically to things that wouldn't bother other children. A child with autism may break her arm in a fall and never cry. Another child might bash his head on the wall without a wince. On the other hand, a light touch may make the child scream with alarm.
In some people, the senses are even scrambled. One child gags when she feels a certain texture. A man with autism hears a sound when someone touches a point on his chin. Another experiences certain sounds as colors. (Source: excerpt from Autism: NIMH)
Some people with autism display remarkable abilities. A few demonstrate skills far out of the ordinary. At a young age, when other children are drawing straight lines and scribbling, some children with autism are able to draw detailed, realistic pictures in three-dimensional perspective. Some toddlers who are autistic are so visually skilled that they can put complex jigsaw puzzles together. Many begin to read exceptionally early-sometimes even before they begin to speak. Some who have a keenly developed sense of hearing can play musical instruments they have never been taught, play a song accurately after hearing it once, or name any note they hear. Like the person played by Dustin Hoffman in the movie Rain Man, some people with autism can memorize entire television shows, pages of the phone book, or the scores of every major league baseball game for the past 20 years. However, such skills, known as islets of intelligence or savant skills are rare. (Source: excerpt from Autism: NIMH)