Cuttlefish can pass the ‘snacking test,’ study finds

Cuttlefish that could wait longer for a meal also showed better cognitive performance in a learning task. In that experiment, cuttlefish were trained to associate a visual cue with a food reward. Then the situation was reversed, so the reward became associated with a different cue. “The cuttlefish that were quickest at learning both of those associations were better at exerting self-control,” Schnell said. 

Why cuttlefish have evolved this capacity for self-control is a bit mysterious. Delayed gratification in humans is thought to strengthen social bonds between individuals—such as waiting to eat so a partner can first—which benefits the species as a whole. It may also be a function of tool-building animals, who need to wait to hunt while constructing the tool. 

But cuttlefish are not social species, and they don’t build tools. Instead, the authors suggested, delayed gratification may be a by-product of the cuttlefish’s need to camouflage to survive.

“Cuttlefish spend most of their time camouflaging, sitting and waiting, punctuated by brief periods of foraging,” Schnell said. “They break camouflage when they forage, so they are exposed to every predator in the ocean that wants to eat them. We speculate that delayed gratification may have evolved as a byproduct of this, so the cuttlefish can optimize foraging by waiting to choose better quality food.”

Finding this link between self-control and learning performance in a species outside of the primate lineage is an extreme example of convergent evolution, where completely different evolutionary histories have led to the same cognitive feature.

Among Schnell’s collaborators was Marine Biological Laboratory senior scientist Roger Hanlon, a leading expert in cephalopod behavior and joint senior author on the paper.

Other collaborators include joint senior author Nicola Clayton at University of Cambridge and scientists at Ripon College in Wisconsin and the Karl Landsteiner University of Health Science, Krems, Austria.

Citation: "Cuttlefish exert self-control in a delay of gratification task." Alexandra K. Schnell et al. Proc. Royal. Soc. B. DOI: 10.1098/rspb.2020.3161

Funding: Endeavour Research Fellowship via the Australian Government, Grass Foundation, Royal Society, U.S. National Science Foundation, Sholley Foundation, European Research Council.