Do you play social games casually or competitively?

When you're playing against another person on a social game, do you prefer playing casually (for the fun of it) or competitively (for the top score)?

For me, I enjoy playing social games casually because it's more relaxing and, in my opinion, is more fun. I do sometimes enjoy a bit of competitiveness in games such as in Tetris Battle from time to time, but for most social games, I play casually.