Biologists at the University of Tübingen in Germany have shown that ravens can make decisions by using statistical inference. This finding changes the previous belief that such cognitive abilities were exclusive to primates. The study, published in Current Biology, offers new insight into the thinking processes of birds and the broader animal kingdom.
In the experiment, two ravens were trained to pick from nine colored symbols. Each symbol carried a different chance of delivering a prize, ranging from a low 10 percent to a high 100 percent. The researchers observed that the birds rapidly learned to map each symbol to its probability of yielding a reward. Over time, they began favoring the symbols most likely to provide a prize, effectively demonstrating probabilistic reasoning in decision making.
The scientists found that the ravens continued to select the higher-probability options even when some symbols offered a lower probability than others with greater chances of reward. This tendency persisted beyond the initial training phase, with the birds showing correct decision making even when tested a full month after the experiments were conducted and the conditions were reintroduced. Such persistence indicates a robust understanding of probability and a strong memory for past outcomes.
These results suggest that ravens possess a cognitive toolkit that supports statistical evaluation and memory, aligning with evidence of sophisticated thinking in other species. The authors emphasize that the findings contribute to a broader picture of animal cognition, highlighting that birds can engage in probabilistic assessment at levels once thought to be the domain of primates. The implications extend to how researchers interpret animal intelligence and how such capabilities may be distributed across different lineages. [Citation: Current Biology]
An additional note in the historical record compares contemporary avian cognition with other species, mentioning that even ancient studies referenced statistical analysis in vastly different contexts. This remark underscores the long-standing curiosity about how animals process information and make choices under uncertainty. [Citation: Current Biology]