Six per cent of child in a sample of III children who were adopted into U.K
. families from Romania, and who were systematically assessed at the ages o
f 4 and 6 years, showed autistic-like patterns of behaviour. A further 6 %
showed milder (usually isolated) autistic features. Such autistic character
istics were not found in a similarly studied sample of 52 children adopted
in the first 6 months of life within the U.K. The children from Romania wit
h autistic patterns showed clinical features closely similar to "ordinary"
autism at 4 years but they differed with respect to the improvement seen by
age 6 years, to an equal sex ratio, and to a normal head circumference. Th
e children from Romania with autistic features tended to differ from the ot
her Romanian adoptees with respect to a greater degree of cognitive impairm
ent and a longer duration of severe psychological privation.