A human's ability to sense those around them is an anomaly among other species. Every human being is unique and everyone feels differently, but all feel deeply for themselves and others. Brain May wrote an article about what makes the human race unique: She said that a human's kindness is a unique characteristic. A BBC documentary has also been created which also explores this idea. In the video What Make Us Human, Professor Alice Roberts studies our closest species, chimpanzees. A certain experiment was carried out in which two chimpanzees had to work together to obtain a free snack. The children also did this experiment, but instead of receiving a snack, they received marbles. Once both were finished, the teacher noticed that the chimps just wanted the snack, and if one of them got that snack first, they wouldn't bother continuing to help the other chimp. On the other hand, when the children were tested, there was a control test where both children received an equal amount of marbles and another test