This author's claims fall prey to his own suggestive criticism of theism. The reason that higher education in the sciences and philosophy purportedly reduces religious belief has as much to do with contemporary popular antitheistic indoctrination in those fields as any supposed increase in knowledge, much less baseline intelligence.
In other words, you send young, malleable minds away from their social/familial roots when they are wanting to strike out on their own and make their way as independent adults (i.e., college age), and you put those minds into environments openly hostile to religion as most secular academic settings are today, and it is no surprise that the result is the lessening of religious belief amongst those who come out of those institutions.
And because of this phenomenon, it is also extremely socially unpopular to be strongly religious amongst highly educated and intelligent people today (I should know). The amount of ignorant, bigoted treatment religious people get amongst educated colleagues is inversely proportionate to those aspiring irreligious folks who run is less educated, less secularized circles.
In both cases, the argument is fallacious, trying to establish suggestive causation where none exists. He even admits the argument is fallacious ("correlation does not equal causation") but nonetheless moves full ahead suggesting that it does in this case. I point it out in case someone finds the suggestions somehow compelling--the basis for the argument applies equally to its antithesis (i.e., the claims of indoctrination and the desire for social acceptance).
Further, the same can be said of his claims for why intelligent religious people defend their beliefs (i.e., because we want to rationalize what we already irrationally believe). That's just human nature, and it applies equally to whatever we believe/hold dear, be that theism or antitheism. At the end of the day, we are all human beings trying to grapple with problems bigger than we can actually fully grapple with. This means antitheist or theist, you will believe things without good reason, you will rationalize things you already believe, and you will make logical jumps and leaps of faith based on your existing understanding of life, the universe, and everything.
This article is all boring, boilerplate contemporary antitheist arguments that are chock full of both fallacies as well as healthy doses of ignorance and prejudice, and the only way they make sense is if you already agree with his conclusions.