The chart above illustrates something that is somewhat important, though not surprising. White conservatives are getting less intelligent in relation to white liberals over time (moderates, as usual, remain the dumbest). Since people always ask for them, I put 95% confidence intervals on it. Intuitively this aligns with data about the realignment of college-educated whites to the Democrats.
The results hold (with wider intervals) if you stratify by sex. The pattern also shows up for all races, but I focused on white respondents to control for confounds (nonwhites have lower WORDSUM scores). WORDSUM is a 10-word vocabulary test highly correlated with IQ.
In any case, I’m presenting the result as is. When I post stuff like this I get comments and emails from conservatives that perhaps on mathematical intelligence they do better. That’s fair. But show me the research on this. Just because your group has a lower average IQ doesn’t mean you do, nor does that mean you are any less of a person if your group does.