What has the greater impact on organic search rankings? Facebook Likes or Google +1s?

A study (by fellow Leeds-based agency Stickyeyes) has looked at over 7,000 URLs that rank in the top 20 positions across multiple competitive sectors in Google.co.uk and correlated their actual +1 and Like counts versus ranking position.

The results suggest that +1s have the biggest impact on search rankings…

What has the greater impact on organic search rankings? Facebook Likes or Google +1s? | Econsultancy.