In-person GSS interviews show 7.5% of whites say yes to innate intelligence causing black-white income gaps. Phone interviews drop to 5.4% (p=.008). Web interviews fall to 3.5% (p<.0001). Interview mode effects vanish after controlling for education, politics, WORDSUM. White interviewers get 7.9% white endorsement (2015 in-person). Black interviewers get 4.1% (p=.00013). Controls widen gap to 6.1% white interviewer vs 2.1% black (p<.0001). Low hereditarian rates persist as genuine rejection, not just social desirability. Propaganda since Civil Rights succeeded in suppressing hereditarian views. 5-10% hereditarianism among whites is believable reality. Counter-propaganda needed to shift views.