Humans descended from monkeys. That’s what scientists believe. Past studies show that monkeys and humans have a lot in common. What humans feel, are also felt by monkeys. A recent study shows that even monkeys feel depressed and regretful over the past bad decisions they have made. Researchers from Yale School of Medicine, believe that not only humans feel regretful, but monkeys as well. During the study, the Rhesus Monkey was used to study how primates react to “disappointing” stimuli. In the study, one researcher played Rock, Paper, Scissors with the monkey. If the monkey won, it will receive a large container of juice. But if it lost, the monkey won’t have any. The monkey’s neuronal function was recorded, and it shows that when the monkey lost, there was a reaction of the monkey’s dorsolateral prefrontal cortex and the orbit frontal cortex, the two regions of the brain that deal with memory and regret.