If he were biased against the concept of social class like he is against IQ, he could use the same tactic: According to GSS data, the correlation between father's education and offspring income is a paltry .13, and the standard deviation (sd) for people with the most educated dads is $42,000, while it is only $33,000 for those with dads who only finished high school. For non-nerds who don't know stats, sd is a measure of how spread out the scores are for a sample of people, in this case, individual incomes.
Turns out, people in the smartest category are diverse on many variables, not just income. I'll give you the sd for the middle and highest IQ categories to show what I mean.
Standard deviation for average intelligence people and those in the smartest category
Middle IQ 2.4
Top IQ 2.5
Middle IQ 12.6
Top IQ 14.4
Middle IQ 1.3
Top IQ 1.6
Middle IQ 2.7
Top IQ 2.8
Confidence in the Existence of God
Middle IQ 1.3
Top IQ 1.7
In every case, intelligent folks are more diverse than ordinary people. Compared to the middle, smart people are simply all over the place in terms of education, job prestige, politics (higher scores mean more conservative), church attendance, and belief in God. Humans beings are so complicated, it's hard to predict which box a person will fall into, and it's even harder when the person is very smart.
This reminds me of the argument that Michael Levin made in Why Race Matters that, because whites are more intelligent, on average, than blacks, they have greater free will, and thus perhaps greater responsibility for their actions.
(You might argue that the sd is higher for smart people simply because their means are higher, thus one can expect the sd's to also be larger. Actually, the means for political orientation, church attendance, and confidence in God are lower for the smart group.)
UPDATE: I am also reminded of what is said about Jews, a famously smart group: two Jews, three opinions.