ROME (Web Desk) – It seems like second nature to think of numbers from one to ten increasing on the right when you lay them out, but research shows it goes much deeper. It may surprise you to learn that at only seven months old, humans recognize this numerical relationship, but now a new study suggests that humans aren’t just the only species to make this connection, which scientists call the mental number line.
A new study conducted by researchers from Italy has discovered that newborn chickens, just three days of age, recognize the mental number line, equating the smaller numbers with the left side and larger numbers with the right. In order to accomplish this, Rosa Rugani, who is with the Department of General Psychology at the University of Padova in Italy, along with her colleagues, trained several chicks to search for their treats that were hidden behind cards.
In the first round, each card bore five printed red dots. Gradually, new cards were introduced, bearing different numbers of dots – some had only two, while others had eight. As the trials continued, the birds seemed to establish a relationship between the three different digits, walking to the left when they saw smaller numbers, but stepping to the right when larger numbers came up.
“In our experiments, 3-day-old domestic chicks, once familiarized with a target number (5), spontaneously associated a smaller number (2) with the left space and a larger number (8) with the right space. The same number (8), though, was associated with the left space when the target number was 20,” the researchers recorded in the journal Science.
From the experiment’s results, the researchers suspect that the ability to map numbers may actually be older than the concept of numbers, predating it by millions of years of evolution. Consequently, it could be said that counting is much more of the experiment suggest that the tendency to map number from left to right has its origins millions of years prior to the emergence of the number concept, relying on the right hemisphere of the brain.
“We have brains that evolved for fighting and finding food, not for doing calculus,” said Tyler Marghetis, from the University of California, San Diego, who was not involved in the study but has conducted his own research on the mental number line. “So one of the hopes of this kind of research is that it will tell us something about the basic building blocks we have access to in building up these more human concepts.”
