2. How early is too early?
Fifty percent of parents report features of autism in their children by 2 years of age and 93
percent indicate recognition of symptoms by age 3. Similarly, Asperger’s syndrome, while being
recognized later than autism, is also noted early by parents, although diagnosis does not typically
occur until 11 years of age (Howlin & Asgharian, 1999). About half of these children with
autism, conversely, are diagnosed by 5 or 6 years of age in the United Kingdom, while in the
United States the average is 3–4 years of age for diagnosis (Filipek et al., 1999; Howlin & Moore,
1997). Baird et al. (2001) note a trend toward a mean diagnosis of 2.7 years. They describe this
development as encouraging. We are more cautious, and would note that early diagnosis is a good
development only if the diagnoses are reliable, have good predictive validity, and prove useful in
assisting in better care and prognosis. At this juncture all of these points require further study and
validation, although initial efforts are promising.