I love these myths that come up from places deep inside the paranoid SEO mind. A Google Webmaster Help thread has one webmaster claiming his rankings dropped in Google because his site was hit by a "bounce rate attack."
The webmaster wrote:
My website has recently seen a dramatic increase in bounce rate. Our bounce rate is typically between 1% to 3% on a monthly basis. However, starting in December our website has been attacked (for lack of a better term) by someone trying to artificially increase our bounce rate in an effort to decrease our search engine ranking- and they have succeeded.
Well, Google has said (believe them or not) that they do not use Google Analytics data within the ranking algorithm. They also said numerous times that they find bounce rates from the search results to a web page and back to be a spamable and noisy metric and don't use that also. And despite all this Google+ social stuff Google is working on, they currently barely use those metrics in the search ranking algorithm.
So to think a bounce rate attack can have a direct impact on your rankings, well, is not proven by what Google tells us.
Now, of course, you don't have to believe what Google tells us and then the bounce rate attack theory can work.
Forum discussion at Google Webmaster Help.
Image credit to BigStockPhoto for bounce rate