Data from: Long-tailed macaques (Macaca fascicularis) can use simple heuristics but fail at drawing statistical inferences from populations to samples

Human infants, apes, and capuchin monkeys engage in intuitive statistics:
they generate predictions from populations of objects to samples based on
proportional information. This suggests that statistical reasoning might
depend on some core knowledge that humans share with other primate
species. To aid the reconstruction of the evolution of this capacity, we
investigated whether intuitive statistical reasoning is also present in a
species of Old World monkey. In a series of 4 experiments, 11 long-tailed
macaques were offered different pairs of populations containing varying
proportions of preferred vs. neutral food items. One population always
contained a higher proportion of preferred items than the other. An
experimenter simultaneously drew one item out of each population, hid them
in her fists and presented them to the monkeys to choose. Although some
individuals performed well across most experiments, our results imply that
long-tailed macaques as a group did not make statistical inferences from
populations of food items to samples but rather relied on heuristics.
These findings suggest that there may have been convergent evolution of
this ability in New World monkeys and apes (including humans).