No, IQ is defined as mental age divided by chronological age and multiplied by 100, so it is a quotient of two positive numbers and must therefore be non-negative. The normal curve that gives the distribution of IQ shows the IQ scores from 0 to an unlimited upper bound. The area under the normal curve that lies between 0 and any given IQ yields the corresponding percentile, i.e., the percent of people at or below that IQ.
In the graph above, the percentile corresponding to an IQ of 85 is 2.4% + 13.6% or about 16%. This means that about 16% of people have an IQ at or below 85.
