Reading at 2 is well-attested by multiple sources.
The IQ was a case of going back to the original kind of IQ test for children, mental age divided by physical age. At the age of 6 he performed at a level to be expected of a 14 year old on the Stanford-Binet test. At the extremes of these tests, the bell curve approximation. So yes, his IQ was measured that high. But it is not strictly comparable to adult IQ tests.
It should be noted that Terrence Tao's early achievements were well documented because he met Dr Miraca Gross of New South Wales at age 3, who was running a longitudinal study of Australian gifted children. Tao, of course, wound up as the star of the approximately 60 children in the study.
The IQ was a case of going back to the original kind of IQ test for children, mental age divided by physical age. At the age of 6 he performed at a level to be expected of a 14 year old on the Stanford-Binet test. At the extremes of these tests, the bell curve approximation. So yes, his IQ was measured that high. But it is not strictly comparable to adult IQ tests.
It should be noted that Terrence Tao's early achievements were well documented because he met Dr Miraca Gross of New South Wales at age 3, who was running a longitudinal study of Australian gifted children. Tao, of course, wound up as the star of the approximately 60 children in the study.