That’s the greater variability theory. The male median is also higher so when you combine the two the long tail to the right will be dominated by males, so will the long tail on the left but to a lesser extent.

Many IQ tests have been designed to minimize the difference between males and females, primarily by reducing g-loading. Males pull ahead after puberty, prior to this they have an IQ disadvantage. So you have to take these factors into account when trying to make a fair and proper assessment.