Rihanna was at the Laugh Factory comedy club with six of her friends, downing drinks and listening to Dane Cook do his thing on stage. Then when the bill came, a measly $80, Rihanna asked her waiter what the biggest tip he ever received was. He answered, "$100." So Ri-Ri slapped $200 into his hand and said, "Now I'm your biggest tip." Amazing right? But the question is why did Rihanna give the waiter a big tip? Was it genuinely out of the kindness of her heart? or was it to make herself feel better?

According to a new study by the Harvard Busniness School, when you donate money and it makes you feel happy, the feeling isn't necessarily coming from doing a good deed. IT comes from your subconscious feeling that you're well off and more powerful than poor people.

Don't believe us? Check out the full article at Health.com. And for more celebrity scoop, listen to "Mark & Kristin's Hollywood Round Up" every morning at 5:20, 6:20, 7:20 & 8:20!

-Mark & Kristin

KA