5. RHESUS MONKEYS
What Makes Them Smart: These monkeys share 93 percent of their genetic DNA with humans. As a result, they have facial expressions and emotions similar to people. Additionally, rhesus monkeys are believed to be self-aware, and have the ability to learn and make self-decisions.
Recent Discovery: Rhesus monkeys almost have college students outsmarted in simple math. A study showed that when rhesus monkeys and college students were given addition problems to do without the use of language, the animals finished as fast as the humans. (Digital Journal)