Do links from Facebook and Twitter help the rankings in a search result? Possibly.
No one except the search engines really know just how much weight and how important a social media presence is for the search engine rankings.
There are, however, a lot of misinformation on the web about this:
A social media presence is important, but just what it does for the search engine rankings is not clear. If it is important, it is getting likes and re-tweets from those with credibility are probably going to be the key.