This paper provides a general overview of the complexity of this developmental disability by summarizing many of the major topics in autism. For many years, the most cited statistic is that autism occurs in 4.5 out of 10,000 live births. This was based on large-scale surveys conducted in the United States and England. Autism is three times more likely to affect males than females. This gender difference is not unique to autism since many developmental disabilities have a greater male to female ratio.
Many autistic infants are different from birth.
As infants, they are often described as either passive or overly agitated babies. These individuals are often referred to as having 'regressive' autism. Some people in the field believe that candida albicans, vaccinations, exposure to a virus, or the onset of seizures may be responsible for this regression. During childhood, autistic children may fall behind their same-aged peers in the areas of communication, social skills, and cognition. One characteristic which is quite common in autism is the individual's insistence on sameness or 'perseverative' behavior.