It is very encouraging that the number of girls who score high in the SAT section of Math has gone up over the past three decades. The children are defined as “highly gifted in mathematics” (by Study of Mathematically Precocious Youth) if they score at least 700 on the quantitative section of the SAT before the age of 13. Recent study by Makei and others point out that the ratio of boys to girls have shrunk in the upper tail of the performance. This study also finds similar parallel results for tests conducted in India. For example, the ratio of boys to girls in top math scores in SAT in the United States for the high achieving 7th graders have shrunk from 8:1 in the past to 2.5:1 recently.
However, it has been argued that the performance of girls in the upper tail of scores in SAT does not necessarily mean that they have extremely high intelligence in mathematics. Both prior SATs and the revised one in 2016 are multiple choice tests that do not necessarily require sophisticated problem solving skills or test concepts that are explained in the higher levels of mathematics. This is not to say that the girls who have top scores in SATs are not bright.
We have to encourage girls to not only score well in SATs but also take part in various math competitions that are available through out the year and of varying levels of difficulty. Problem solving skills are critical in this competitive world and high SAT score in mathematics section is just one data point that shows how girls are doing better now. World will definitely benefit from more girls math researchers, Field medalists, IMO, and Putnam competition winners. Scoring high on math section of SAT is necessary but by no means sufficient at all to show that gender gap has narrowed in the field of higher level mathematics.