What do you mean you got a grape? I only got a carrot! iStockphoto hide caption itoggle caption iStockphoto Shots - Health News Why Do You Care About Fairness? Ask A Chimp September 18, 2014 Squirrel monkeys, chimps and humans: Two among these are willing to give up an unfair advantage, but why? It's about greasing the social wheels, scientists say.