In the last month, 33% of users surveyed said they updated their status. A year ago, that number was 50%.
And in the same time period, 37% said they shared photos, down from 59% a year ago.
Facebook denies that its users are sharing less.
"People continue to share a ton on Facebook and the overall level of sharing has remained not only strong, but similar to levels in prior years," the company said in a statement.
The good news from the GWI survey is that users are still highly engaged in other ways – watching videos, liking things, commenting, and messaging.
But a decline in sharing could be a problem for Facebook, as a site with less content is a more boring and less engaging site.
Proof that Facebook is trying to get people to post more content on the site? This annoying as hell feature that prompts users to share the last link they copied to their iOS clipboard.