Do people with larger brains have higher IQ scores? The following figure shows the result of a study conducted on 40 volunteers, 20 selected for their high IQ - 130 or more - and 20 selected for their low IQ - 100 or less. The researchers' choice of studying high and low IQ scores only is reflected in the gap on the scatterplot for mid-range IQ scores. Brain size was measured by magnetic resonance imaging (MRI). The MRI count is the number of "pixels" the brain covered in the image. IQ was measured by the Wechsler test. Of the 40 volunteers, 20 were women (red) and 20 were men (black). 150 140 130 120 2 110 100 90 80 70 800,000 900,000 1,000,000 1,100,000 Brain size (MRI pixels) From the plot, the researchers should conclude men generally have a larger brain size than women. O there is dependency of IQ on the brain size. O IQ depends on the gender