I have never posted a question or answer on Expatriates.SE, but have been very active on Stack Overflow in the past, yet when I search for my name in Google Expatriates.SE comes much higher in the result then Stack Overflow.
As every posting I have made on SE, has my name as a link back to my profile on SE, there must be someone being done to the links or sitemap files by the SE engine to point Google in the wrong direction.
It may something daft like I have enough rep on Stack overflow that the links on my profile page don’t get a “no follow”, but the links on all the other profile pages do get a “no flower”. Profile pages all link to each other.
(I do not wish to have to put a false name on all my profiles apart from Stack Overflow just so google gets it right, or even delete all account apart from Stack Overflow.)