Mental impairment multi-dimensional problem.. Mortality rate in the weak-minded high society

- The incidence of mental impairment:

The proportion of weak-minded in the community about 2.3% of the total population, especially in childhood. And may account forup to about 5% of the births, the mortality rate is high, and less than an IQ of 70 according to the Wechsler scale of intelligence.

And between them and the ordinary are