Not all college students are created equal when it comes to math proficiency, but surely they're all at least more capable than a fish, right?
Think again. According to National Geographic, common mosquitofish show roughly the same numerical skills as college students in some laboratory tests.
Mosquitofish are tiny but hardy freshwater fish named for their appetite for mosquito larvae. Because they are highly social and seem to monitor the size of their groups, scientists have long suspected that they had at least some basic math proficiency. After a previous study demonstrated that the fish can count, researchers wanted to see how far their math skills could go.
A special experiment was designed in which lone fish were trained to associate a door bearing a certain number of geometric shapes with the path to rejoining a larger group. They were then placed in a tank with two doors, each bearing a symbol representing a different number, and given a choice of swimming through one of them. The fish were motivated to choose based on their natural disposition to prefer larger groups over smaller ones.
The test was designed so that researchers were not only able to identify how well the fish counted, but also how adept they were at differentiating ratios.
The results were surprising. Not only could the fish tell the difference between small numbers such as four and eight, but they could differentiate between quantities as large as 100 and 200.
Scientists learned that not all ratios were as easy for the fish to recognize, however. For instance, the fish differentiated between ratios of 1:2 (8 versus 16) or 2:3 (8 versus 12) with ease, but they struggled when the ratio became 3:4 (9 versus 12). In other words, when the amounts on the doors were closer in number, the fish failed to tell them apart.
But their failure isn't shocking. It turns out that humans also find ratios closer in number more difficult to differentiate.
Imagine walking into a room with two piles of red balls. If you were told one pile had 50 balls and the other pile had 100, then you could probably identify which pile was which with ease. But what if one pile had 50 balls and the other pile had 60? It might be more difficult to see the difference.
Interested in quantifying how the numerical skills of fish compare to those of humans, the researchers decided to perform a similar test on college students.
While the students were universally more accurate than the fish, they showed the same degraded ability to judge number differences as ratios shifted from 2:3 to 3:4. In other words, its not ridiculous to compare the abilities of fish and college students at differentiating ratios.
"You just don't expect interesting results like this when dealing with animals like fish," said study leader Christian Agrillo of the University of Padova in Italy. "We thought this was really incredible."
Whether these results are interpreted as boding well for the fish or poorly for the average college student is left to the discretion of the reader.
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