University students, you are about as smart as your fish — at least that’s what a recent study that compared the numerical skills of mosquitofish to college students may suggest.
The study found that the fish could differentiate between small numbers such as 4 and 8, and also large quantities such as 100 and 200, a surprising feat for the animals that researchers found incredible. “You just don’t expect interesting results like this when dealing with animals like fish,” study leader Christian Agrillo of the University of Padova in Italy told National Geographic.
However, what was perhaps more surprising was that when the numerical skills were applied to ratios, experiments showed that the ability of the fish closely matched the abilities of their human college student counterparts.
An experiment for the study trained lone fish to associate a door labeled with a certain number of geometric shapes with a specific path to joining a larger group of fish. The fish were later placed into tanks where they were given the choice between two identical doors with a different number of symbols.
At first, the fish were clueless as to where to go, yet eventually began to move towards their preference for larger numbers, leading them to choose the correct door. The researchers also found that the fish could easily differentiate between ratios of 1:2 or 2:3, but had difficulty with the ratio of 3:4, which demonstrated that the fish couldn’t tell the doors apart when the numbers were closer together.
To compare the numerical skills of the fish to humans, researchers presented a similar test to a group of 25 university students, which asked the students to differentiate between groups of large numbers in two seconds. The students were more accurate, but encountered similar problems as the fish when trying to tell the difference between numbers as the ratios shifted from 2:3 to 3:4.
Researchers believe this finding may demonstrate that humans, fish, and other vertebrates share a common ancestor that possessed similar abilities to process numbers.