Originally Posted by Bostonian
A meta-analysis found that stereotype threat is not hurting the performance of girls in stereotyped domains:

https://www.ncbi.nlm.nih.gov/pubmed/25636259
J Sch Psychol. 2015 Feb;53(1):25-44. doi: 10.1016/j.jsp.2014.10.002. Epub 2014 Nov 13.
Does stereotype threat influence performance of girls in stereotyped domains? A meta-analysis.
Flore PC1, Wicherts JM2.
Author information
Abstract
Although the effect of stereotype threat concerning women and mathematics has been subject to various systematic reviews, none of them have been performed on the sub-population of children and adolescents. In this meta-analysis we estimated the effects of stereotype threat on performance of girls on math, science and spatial skills (MSSS) tests. Moreover, we studied publication bias and four moderators: test difficulty, presence of boys, gender equality within countries, and the type of control group that was used in the studies. We selected study samples when the study included girls, samples had a mean age below 18years, the design was (quasi-)experimental, the stereotype threat manipulation was administered between-subjects, and the dependent variable was a MSSS test related to a gender stereotype favoring boys. To analyze the 47 effect sizes, we used random effects and mixed effects models. The estimated mean effect size equaled -0.22 and significantly differed from 0. None of the moderator variables was significant; however, there were several signs for the presence of publication bias. We conclude that publication bias might seriously distort the literature on the effects of stereotype threat among schoolgirls. We propose a large replication study to provide a less biased effect size estimate.

KEYWORDS:
Gender gap; Math/science test performance; Meta-analysis; Publication bias; Stereotype threat; Test anxiety

Suggest reading the inputs into the study cited, as well as the study itself for an understanding of the inputs to these numbers. One of the feeds into it (linked below) identified instrumental variables--including ubiquity of stereotype threat--that weren't captured in the methodological design of your linked article.

It is important to note that it's not properly understood whether stereotype threat in this context is global (within a domain) or local (specific to an event), and within which range of critical values. This matters enormously in model specification and conclusions reached. Omnipresent stereotype threat is much more difficult to empirically isolate to generate significance, as it makes modelling collinearity a beast; but absence of evidence of an effect in a poorly specified model is not evidence of absence.

See, particularly, the bolded.

https://www.ncbi.nlm.nih.gov/pubmed/23356523

Quote
Stereotype threat has been proposed as 1 potential explanation for the gender difference in standardized mathematics test performance among high-performing students. At present, it is not entirely clear how susceptibility to stereotype threat develops, as empirical evidence for stereotype threat effects across the school years is inconsistent. In a series of 3 studies, with a total sample of 931 students, we investigated stereotype threat effects during childhood and adolescence. Three activation methods were used, ranging from implicit to explicit. Across studies, we found no evidence that the mathematics performance of school-age girls was impacted by stereotype threat. In 2 of the studies, there were gender differences on the mathematics assessment regardless of whether stereotype threat was activated. Potential reasons for these findings are discussed, including the possibility that stereotype threat effects only occur in very specific circumstances or that they are in fact occurring all the time. We also address the possibility that the literature regarding stereotype threat in children is subject to publication bias.

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