Has this been proven? If so based upon what specific factors? "Background" and "upbringing" encompass a multitude of meanings. I also have not personally ever s

Has this been proven? If so based upon what specific factors? "Background" and "upbringing" encompass a multitude of meanings. I also have not personally ever seen a job ad for "Data Scientist with rural WV / trailer park upbringing" yet that cohort is likely to have a near zero representation. I have seen things offered by "race" and sex. Race seems to be determined by melanin level and self identification, not DNA sequencing.