Research Overview:
The ability to understand number and counting is often thought to be specific to humans. Over the last few decades, studies have shown that terrestrial mammals and birds can understand various numerical concepts, and that in primates at least, these numerical concepts can be very advanced.
There are at least four types of skills that underlie basic human competence with number and math.
- Recognizing numerosities – distinguishing, for example that “threeness” is different from “twoness”; i.e., knowing that a set of 3 objects is distinct from a set of 2 objects.
- Understanding relative numerosity – realizing that numbers form an ordered series, incorporating the relationships of more and less; i.e., 1 is less than 2, 2 is less than 3, and so forth
- Mapping numerosities to symbols – learning for example that “1” goes with “oneness”, “2” goes with “twoness”.
- Manipulating numerals – e.g. addition and subtraction.
Do dolphins have the capacity for these kinds of skills? If so, what are their competencies in relation to the rest of the animal kingdom and to human child development? DRC’s Research Department, led by Dr. Kelly Jaakkola, is addressing these questions.
In our “Less” project, we researched the ability of dolphins to understand the first two concepts — numerosity and relative numerosity. Two of our dolphins, Talon and Rainbow, participated in this study. We began by showing each dolphin two boards with different numbers of dots on them: 2 and 6, for example. First, we asked them to always pick the board with 2 dots on it, no matter where the dots were on the board or what size they were. Learning this task meant that Talon and Rainbow understood that 2 is different than 6, which is the concept of numerosity. The next step was to test with other number pairs that were new to the dolphins, and always ask Talon and Rainbow to choose the board that had the fewest dots on it. The ability to pick out the smaller number without being trained on that specific number pair meant that they understood the concept of “less” (i.e. relative numerosity).
References:
Read about the study in the American Psychology Association’s Monitor on Psychology (Vol. 36, No. 8).
