The animal that is considered the closest to humans is the chimpanzee. They share over 98% of our genes and have similarities in behavior, emotions, and cognitive abilities. Chimpanzees demonstrate altruism, empathy, and even use tools to complete tasks. They can also communicate with each other through various vocalizations and body language. Due to their similarity to humans, chimpanzees have been used in scientific research to study diseases and behavior. However, their use in research has become controversial due to ethical concerns and the recognition of their high level of intelligence and complex social lives in the wild.