Workers aren't supposed to be smart, so the children of workers who are smart get bullied for it. Some of them make art or do science(varying kinds and levels of quality) relating tho their experience. They are taught not to analyze material conditions, so they assume it was just them being smart they were bullied for. Now people not only assume they are bullied because they are smart, but that they are smart because they are not liked. Repeat a few generations, as well as weird shifts in popular culture and increasing aleination and atomization, and you get the "sigma male."