And, I've finally just finished reading the study you linked me in it's entirety. They list five separate reasons why their test might not have gotten the same results - all of which have nothing to do with faulty US methodology.

1) It wasn't a random sample. Geez, even I know that's a big red flag. "First, our current sample of high school students might not be representative of the wider population of high-performing high school students in the Netherlands. Because circumstances forced us to use convenience sampling instead of random sampling, our sample might not be completely representative of the population of students we wanted to study."

2) The Netherlands has a very different culture. For examples, children grow up with comprehensive sex education from age 4 that teaches them to relate the other sex as people. "Second, it is possible that the students in our sample lack characteristics that are needed for stereotype threat to occur, including the belief in gender stereotypes or identification with the math domain. It might be that a large share of students in our sample did not believe the stereotype that boys are typically better in mathematics than girls."

3) "Third, our chosen manipulation of stereotype threat could have been ineffective."

4) "Fourth, there might be issues with the outcome measure used in our study. It could be that the selected math test did not elicit any threat, for instance because the wrong types of items were used or because the test was too easy."

5) "Fifth, the setting could have been insufficiently threatening for stereotype threat effects to occur, while the control condition might not have been sufficiently safe (i.e. devoid of threat) for girls to perform well. Specifically, if stereotype threat is not sufficiently removed in the control condition, no differences in math performance between the stereotype threat condition and the control condition are expected because both groups will experience threat (Spencer et al., 2016). "

In other words, you've got to be kidding me that you presented this as some kind of definitive evidence of anything at all!!!