Evidence of statistical reasoning in giraffes suggests relatively large brains are not required to evolve complex statistical skills. The researchers propose the ability to make statistical inferences may actually be widespread in the animal kingdom.
SCARLETT HOWARD: Humans make decisions using statistical information every day… and as it turns out, humans aren’t alone in using statistical inferences to make decisions. Great apes, long-tailed macaques and keas have all been shown to use the relative frequencies of items to predict sampling events.
Now a new study has added giraffes to this list. The research, published today in Scientific Reports, shows giraffes can use statistical inferences to increase their likelihood of receiving carrot slices rather than zucchini… Until now, primates and birds were the only animals to show evidence of statistical reasoning. Both are considered to have large brains relative to body size, which is often linked with higher intelligence.
Researchers at the University of Barcelona, University of Leipzig, and Max Planck Institute for Evolutionary Anthropology wanted to test whether an animal with a small brain relative to its body size could perform statistical reasoning.
Working with four giraffes, the researchers placed different proportions of carrot and zucchini slices into transparent containers to test if the giraffes could predict a higher likelihood of receiving a carrot in three tests of different treat quantities.
Each test consisted of 20 trials in which a researcher selected a piece of food from each container without showing the giraffe. The giraffe then touched the hand it wanted to eat from, using only the information it had from the containers.
Giraffes were an ideal choice. They have already demonstrated an ability to perform quantity discrimination (being able to tell a larger amount of items from a smaller amount), and their social systems and dietary breadth have been linked with the emergence of complex cognition…
The combined results informed the researchers whether giraffes were using relative frequencies (statistical reasoning) or simply comparing absolute quantities of their preferred or non-preferred food. Since the giraffes succeeded in all three tests, the researchers concluded they had used statistical inferences…
Evidence of statistical reasoning in giraffes suggests relatively large brains are not required to evolve complex statistical skills – at least in vertebrates (animals with backbones). Furthermore, the authors propose the ability to make statistical inferences may actually be widespread in the animal kingdom. The question now is: how many other animals with small brains relative to their body size could also succeed in this task? SOURCE…