Arithmetic

Arithmetic is a branch of mathematics that deals with number systems and operations with such numbers such as multiplication, division, addition, and subtraction. Modern human western educational systems focus heavily on arithmetic. Thus while the ability to learn arithmetic is universal to human populations, arithmetic itself is not universal to all human groups.

The earliest evidence of arithmetic in human evolutionary history dates to about 35,000 years ago. Baboon fibulae covered with scratches presumed to be tallies, including the “Lebombo bone” (35,000 years old) and the “Ishango bone” (25,000 years old), have been found at ancient human sites in Africa. The marks are presumed to be for counting. Others have suggested that they are evidence of more complex mathematics, and still others believe they have no mathematical significance.

There has been a significant amount of experimentation on mathematical skills of other animals. The ability to approximate numerical magnitude is widespread and extends even to birds and amphibians. Chimpanzees have been demonstrated to have the ability to count and sum small numbers. Other primates also have some simple numerical skill; one study of rhesus macaques demonstrated the mastery of abstract numerical rules (in this case, ordering numbers), and another showed they are capable of simple addition (although not as accurately as human college students). However, other studies have indicated that pigeons have abilities on par with this.

Neuroimaging studies of humans and other primates have indicated that a region called the intraparietal sulcus is highly involved in mathematical tasks. Lesions of the nearby left angular gyrus are associated with deficits in mental arithmetic abilities, although the neural basis of these skills is not fully understood. Notably, numerical processing in human children and rhesus monkeys causes increased activation of the prefrontal cortex when compared with human adults. It has been suggested, therefore, that this area is the early association cortex for numerical magnitude in both humans and other primates.

Interestingly, calculation deficits associated with lesions of the intraparietal sulcus are commonly found with “finger agnosia” (the inability to distinguish between individual fingers), suggesting that learned counting on fingers by children may be imprinted into cortical pathways. Along similar lines, people raised in different cultures or taught to solve problems with different methods exhibit differences in brain activation during mathematical problem-solving. Again, this suggests that culture and learning through human childhood may have a significant impact on neural patterning and mathematical skill.