earnestness

noun1

1. •
   The quality of being earnest; sincerity; seriousness.

   • 22 March 2012, Scott Tobias, AV Club The Hunger Gameshttp://www.avclub.com/articles/the-hunger-games,71293/ She’s joined, on the boys’ side, by Peeta (Josh Hutcherson), a baker’s son whose earnestness masks a gift for strategy that Katniss lacks.
   • She spoke with great earnestness about the issue.