Very often, the reaction I get when telling people that I'm a research student in Physics "Wow! Physics!"
The thing is, scientists aren't superficially smart. Neither do they have robotic servants to help them with chores at home. In fact there are many scientists who failed maths and basic sciences as a child. The recently unveiled Nobel Prize winner in medicine, Sir John Gurdon, was thought to be "too stupid" by his science teacher. And many prominent physicists don't fully understand Quantum Mechanics. And more importantly, a lot of science bloggers, who are supposed to be experts in their respective fields, had a bad record at school.
Science really isn't difficult. But I've heard people saying that perhaps our brains are wired that way. That, my friend, is definitely not true. I believe the difference lies in the source, and journalists are the biggest culprit here. Very often when we read about a certain article in the newspaper, we nod along as if every crap written in there is right. But when we read something within the domain of our expertise, we start to think "gosh where does this crap come from?"
A truly intelligent person is not someone who can utter complex terms that other people don't understand, but someone who can make complex terms understandable to everyone else. A man like Richard Feynmann.
So a scientist is no smarter than an accountant, lawyer, or economist. He's just lucky.
p/s: But we do have to admit that most of the smartest people that ever lived were physicists.