Baby chicks can count, according to a new study, and they appear to carry out this process moving from left to right.
This new study reinforces earlier ideas that animals do not require words for numbers in order to have a sense of value.
Number lines, such as those studied by students in grade school, place large values to the right of smaller numbers, in a manner similar to that utilized by the chicks. Although this practice is common around the world, no one has been able to show why this is the case.
Chicks just three days old were trained to head toward a panel with five dots on it in order to obtain food. They then removed the marker, replacing it with a pair of panels with two dots, one to the left, and one to the right of the position of the original card.
The young birds preferentially walked toward the one on the left. When a similar trial was carried out with eight dots on the panel, the chicks moved to the right more than to the left. This suggested to researchers that chicks use a number line in a similar manner to human beings.
A second round of experiments was carried out using cards with eight, 20, and 32 dots, with similar results.
"Our results suggest a rethinking of the relationship between numerical abilities and verbal language, providing further evidence that language and culture are not necessary for the development of a mathematical cognition," Rosa Rugani from the University of Padova in Italy said.
Spatial mapping, or the ability to organize numbers according to value, has been found in other animals previous to this study. However, investigators still question the source of this number sense. It is likely the ability evolved in an ancient animal that was an ancestor to both birds and mammals, including humans.
"I would not at all be surprised that the number spatial mapping is also found in other animals, and in newborn infants," Rugani stated in a press release.
This activity is carried out in the right parietal cortex of human brains, and further research will examine whether or not a similar region of the brain is used by the brain for mapping numbers.
In April 2009, Rugani released the results of a study that showed chicks are able to count, at least up to five.
A study released in 2013 showed that mathematical ability in human beings begins to develop during infancy. Even newborns just two days old have been shown to have an innate sense of numbers.
Investigation of spatial mapping in baby chicks was published in the journal Science.
