Monkeys understand what numbers are and make use of their numerical knowledge in their decision making processes. They are also willing to both learn and use mathematical symbols when rewarded with incentives. These notions have been reinforced by a study demonstrating a higher mathematical capacity in monkeys than previously thought. More specifically, the experiments indicate the ability of monkeys to memorize and implement knowledge of 26 distinct mathematical symbols per Tech Times.
The animal research seeking to reveal data about primate math skills was led by a neurobiologist at Harvard Medical School and involved training rhesus monkeys to learn a number system. Once the monkeys knew their math symbols, they were tested by having to make choices between symbols representing smaller numbers and larger numbers. Since there was a reward associated with the larger numbers, there was a motive to choose the bigger of the two and this is what happened over 70 percent of the time according to New Scientist.
The use of rhesus monkeys in the research is quite important because these monkeys developmentally diverged away from humans at a much earlier time in history according to Live Science. Moreover, rhesus monkeys are believed to have separated from the human lineage approximately 19 million years earlier than chimpanzees, which are already known to have math ability. Furthermore, if rhesus monkeys possess mathematical skills, then the ability to use math becomes a more fundamental or deep rooted ability in primate brains.
Numerous animal psychology studies have been conducted to test the mathematical ability of monkeys. In addition to chimpanzees and rhesus monkeys, the subjects of choice have included macaques, which have also demonstrated numerical capacity per the American Psychological Association. What these additional studies do, is help validate other research and account for differences in individual monkey behavior. Furthermore, like humans, monkeys may have a range of abilities that make some of them more adept or able to learn some things than others, math being one such example.
Monkeys' ability to use math has implications in their natural environment. However, how much they use math is still being studied. Researches seek to identify events or circumstances in which numerical perception takes precedence over other abilities such as auditory or spatial perception. In addition, if used in conjunction with other perceptions, scientists and others seek to understand how math influences monkeys' decisions in the wild. One such study is published in the International Journal of Zoology and reveals that another kind of monkey, specifically vervet monkeys, used "arithmetic-like reasoning" when making foraging decisions.
Primate brains are complex organs capable of amazing things. Continuing studies that test monkeys' mental ability and skills help reveal just what their brains are capable of. By being aware of what monkeys can do with numbers, their interaction with the world can be better understood. Monkeys' quantitative skills also reveal information and raise questions about the importance of math as a factor in human evolutionary development. For example, if monkeys and humans both use math, then this may support the idea that creativity plays a greater role in human development than quantitative ability.