I think your question is an intriguing one. I agree with Clara about people being animals subject to conditioning. We tend to gravitate to, and become pleased by, those things which give us pleasure - unless we're depressed.

Strangely, I don't view 'Hugs' on PC as validation...I view hugs as support and concern. But I do use PC's 'Thanks' in the same way as I use Facebook's 'Like.'