Well if there's a high sensitivity in the test (which to get 0.9 would suggest a lower specificity) then that'd mean it always can tell when a brain deviates fr

Well if there's a high sensitivity in the test (which to get 0.9 would suggest a lower specificity) then that'd mean it always can tell when a brain deviates from the "established" sex. i.e. for people who ahead of time aren't known to be intersex or trans, it would be able to identify them with high accuracy. And the sensitivity vs specificity will depend for each category they are testing for (i.e. testing cis male, cis female, trans masc, trans fem, nonbinary, and some of the different intersex categories). i.e It could be a cheaper test to do than genetic testing and if particularly effective may be useful in identifying genetics associated with different sex characteristics.