Cuttlefish study finds those able to delay gratification the longest are the smartest

Researchers have published the results of a new study focusing on the odd-looking cuttlefish. In the study, researchers provided the first evidence of a link between self-control and intelligence in a non-primate species. In the experiment, common cuttlefish in tanks were presented to foods they commonly eat in separate chambers.

In one chamber was a piece of king prawn, which they could eat immediately. In the other chamber was a live grass shrimp which is their preferred food. However, the cuttlefish could only have the shrimp if they waited and didn't eat the prawn. Researchers tested a range of delay times starting at 10 seconds and increasing the delay by 10 seconds each time the experiment was performed.

All six cuttlefish used for the experiment showed self-control waiting for the grass shrimp, ignoring the king prawn. In testing, the cuttlefish with the most self-control could wait 130 seconds for the grass shrimp, which is comparable with large-brained animals like chimpanzees. Researchers were surprised the cuttlefish would wait for over two minutes for a better snack.

Researcher Dr. Alexandra Schnell from the University of Cambridge Department of psychology was surprised a fast-growing animal with an average lifespan of less than two years would be a picky eater. Researchers also tested the learning ability of each cuttlefish specimen. They used a dark gray marker and a white marker placed in random positions in the tank. The cuttlefish learned to associate one color with a reward, and then the reward was switched to be associated with the other color.

Cuttlefish quicker learn the association and faster to realize the switch were the same ones that showed more self-control in the first task. Interestingly, the same link between better learning performance and better self-control exists in both humans and chimpanzees, but this is the first time it's been shown in a non-primate species.