Although it is a complicated relationship, brain volume (or "size," as measured by MRI) does correlate with intelligence (as measured by performance on intellectual tasks). What is the typical range of those correlations?

.30 to .40                              

Explanation:

In simple words, The average brain size of healthy people is weakly associated with intellect, with a correlation rating of 0.3 to 0.4 out of a possible 1.0. In other terms, brain volume stands about 9 to 16 per cent for human intelligence variation altogether.

The capacity of people to consider innovative concepts, respond to changing situations, benefit from experience, thought abstractly, prepare and purpose vary. Via a variety of loosely linked principles such as cognitive ability and fluid or otherwise crystalline intelligence psychologists have attempted to explore these variations in intellectual capacity.

gamete is the ansewer