What if aliens just aren't clever enough

I've never given a great deal of thought to the notion of aliens living their lives on other planets somewhere in the solar system - I'm pretty neutral on the point. Plenty of weird and wonderful creatures on this planet and plenty of those at are at risk of extinction, which possibly means that we're actually reducing the amount of life in the universe...

Anyway whenever I watch the film Contact, which I enjoy, I am always keenly aware that if the search for ET were left up to me it would be an abysmal failure, even assuming there's anything to find (of course if we're the only place that's inhabited then any abysmal failure isn't really going to be my fault).

I've no idea what "hydrogen times pi" really means or "off-axis". At a pinch I might manage the bit where they whoosh the signal into a TV and do something 'interlacing'-ish. I bet I'd have worked out the 3D primer (sorry, primmer) bit though. That Pioneer plaque that's already up there - wouldn't mean much to me if I happened across it without the Wikipedia explanation.

Probably the bit of the film that made me think how relieved I am that there are many people much smarter than me, on this planet at least, is the part where John Hurt suggests that aliens are likely to be more intelligent (why?!).

I'm assuming this is just a mistake and what the writers were trying to get across is that aliens that can already get in contact with us might also be brighter or more technologically advanced.

If Earth consisted only of people exactly as smart and knowledgeable as me, but no smarter, the planet would do quite well in terms of sarcastic critiques of woo and nonsense but we'd have nothing technological because I don't know how to make it. Admittedly my skills have gone into the life sciences, perhaps if I'd studied astronomy or technology we'd be OK.

But what if all the aliens on all the other planets (let's generously assume the universe is hosting something inhabited other than earth) are full of bright 'people' but none of them happen to know much about radio waves and how to use them as a communication tool. We're already surrounded by plenty of creatures with whom we can't really communicate...

This is the sort of thing that will keep me awake now ;-)