Yep, you’ve read that right (and yep, I haven’t done a mistake in the title). Surprising as it sounds, the Chitika blog recently published a research suggesting that the lower your Google rankings the higher the CTR you’ll see on your ads.

Here’s the link to the article: Google Results, Positioning, and CTR: Not What You’d Expect.
If you think about it, though, there’s some logic there. People clicking the lower results listed by Google are probably clicking on all or most of them (i.e, they are trying harder to find the information in question). That’s why they are also more likely to click on ads (i.e., they are on “click” mode).
Does that mean that you should aim to get your site on those lower results, though? I don’t think so. Even if the higher spots will have a lower CTR they will have a much higher traffic, so the overall earnings will be much higher as well.
The Chitika blog, though, affirms that even taking traffic into consideration things might not be as clear. For example, they say that if the cost (either in terms of money or time invested, or both) to reach the 2nd spot is 50% of what you would need for the 1st spot your ROI would be superior going for the 2nd spot.
I am not quite convinced, but it’s an interesting discussion.