> The presence of bias is purely numerical and is allowed to thrive due to the lack of controls.
This statement is wonderfully self-contradictory. The study overwhelmingly proves the first part wrong. The presence of bias is numerical, certainly, but it is not purely numerical and must actually exist, which is acknowledged after the "and," in contradiction.
> Prestige is an unrelated red herring masking the very human behaviors that account for social gravity in many walks of life.
The study conclusively demonstrates that prestige most certainly is central to academic mobility. Also, biases are among the very human behaviors that account for social gravity.
> This is commonly referred to as implicit bias
Again, contradictory to immediately previous statement. If prestige is a red herring, it can't also be implicit bias unless the implicitly biased individual is intentionally misleading themselves, i.e. demonstrating cognitive dissonance.
> and is generally the most common cause of various forms of selection bias,
Prestige is highly unlikely to be the most common cause of selection bias. Systematic error is a far more common cause of selection bias.
> including racial discrimination from both the majority and minorities alike.
The surprising claim here is that prestige causes racism. But racism has many causes, the most common being that it is learned. In origin, I think it is probably caused by a combination of low intellect, lack of education, irrational fear of diversity, and narcissistic self-interest. And it should be noted that the idea of reverse racism has been employed wherever white supremacy is diminished. It is, IMO, neither legitimate nor valid conceptually and fundamentally a tu quoque fallacy.