I agree that intelligence is rewarded to a point, but I tend to disagree with the last. In my experience, algebra through calculus, up to and including differential equations, were taught in such a way as to promote a real understanding of the subjects, and were, in fact, much easier to grasp with a real understanding in place. This all ended with boundary value problems, where you were lucky to even have a professor that truly understood the subject and was capable of teaching it to more than a handful of the handful of students who came out of differential equations with something more than plug and chug ability. I witnessed a similar line in physics somewhere in the middle of thermodynamics. Correct answers to 5 of 10 problems earned A's in higher level courses- very few, if any, students left these courses with a true understanding of the problems.

Materials (vital to civil engineering) was an interesting intersection of chemistry, physics, and mathematics. A practicing civil engineer need not know much about bonding angles and alloy composition when the problem before him is simply a question of compressive or tensile forces. He can follow traditional construction standards, or consult a database of materials by desired property to choose appropriate materials.

Far too many of my fellow students in Materials earned passing grades without any real comprehension of the subject. It would be frightening to contemplate how many are now practicing civil, mechanical, and even aerospace engineers, if not for the reality that, in industry, they mostly take a free ride on the backs of the true geniuses that came before them.

It doesn't surprise me at all that Tea Party-goers would demonstrate higher scientific comprehension. Having read Andrew Breitbart's description of Tea Parties from the inside (in Righteous Indignation), they sound like the only kind of party worth going to. They seem to be a sanctuary from the sort of irrational and unsubstantiated criticisms that cause great thinkers to abstain from vocalizing their opinions in polite PC company. A safe haven for earnest rational debate and discussion without the intrusion of the smoke and mirrors of charismatic liberals who shamelessly excel at the art of subtle subversion of credibility by implying that one might be a touch racist or a tad bit sexist or mildly homophobic or unconsciously Islamaphobic.

to your last statement-more to do with the market and maybe interviewing skills

the reality is, many engineers try not to learn more than they have to, to get past the tests. more so once you are in a job. we have all has seen Phds who have learned one thing really well-the only thing they will work on and provide no new insights past their field of expertise or even in their area of expertise. Their willingness to apply science and reason outside of their area of expertise is lower.
In fairness, employers encourage that attitude.
There are plenty of engineers who are not working with 19th century physics but of course plenty who do. paths of least resistance

one reason the managers are likely to be less intelligent than the engineers is that our accounting systems show no revenue associated with inventing. It is considered an expense. There is nothing on the balance sheet showing it as an asset-just expense. Thus, our main tool in understanding what's going on in our business, shows engineers inventing providing no value.
hmm-on the outsider thing. I always thought of it as exceptional. I only dated engineers in college. lol

good questions

I did play with mercury. not daily though