you're reading...


Cuttlefish Pass Intelligence Test by Resisting Temptation

New research finds that cuttlefish display human-like intelligence characteristics. Something called delayed gratification, like avoiding that box of cookies while you wait to cook dinner. These squid relatives may be smarter than they look!

Schnell, A.K., Boeckle, M., Rivera, M., Clayton, N.S., & Hanlon, R.T. Cuttlefish exert self-control in a delay of gratification task (2021)Proceedings B, Royal Society Publishing, 288: 20203161, https://doi.org/10.1098/rspb.2020.3161.

Cute & Smart

You may have heard of cuttlefish, a lesser known cephalopod and relative to the octopus and squid, with an adorable name.  These marine molluscs have “W” shaped pupils, 8 arms, and 2 longer specialized arms called tentacles which have suckers to grab prey. Cuttlefish are unique because they have an internal shell called the cuttlebone, which helps control their buoyancy and can often be found washed up on the beach. A cuttlefish has a relatively short lifespan of less than two years and lives a quiet life with a simple social circle. They have the marvellous ability to camouflage and often use this to assist in foraging for prey. Despite their size of only 15-50 cm, cuttlefish have been distinguished for their intelligence. Cuttlefish have been shown to use memory to assist with foraging and even have shown advanced navigational skills.

Cuttlefish have one of the largest brain-to-body size ratios of the invertebrates. (Image Source: Wikimedia Commons, David Sim.)

Scientists wanted to look deeper into the cuttlefish’s intelligence and cognitive abilities.  The scientists were inspired by the “marshmallow test”, which is a 1960’s experiment that presented children with 1 marshmallow and the suggestion to wait a period of time in order to get TWO marshmallows. The study produced often hilarious results (only 30% waited) and also demonstrated the ability of delayed gratification or self-control, meaning waiting in order to gain a better reward. Self-control has been linked to intelligence as it shows evidence the study specimen is able to plan for the future and make decisions. The ability to delay gratification or show self-control has been shown in “smart” animals like apes, crows, and parrots, while failing animals include rodents, chickens, and pigeons.

Putting Cuttlefish to the Test

A scientist from the University of Cambridge and her colleagues tried a similar experiment with six 9-month old common cuttlefish, swapping out the marshmallow for more delicious crustaceans. They first determined what the cuttlefish’ favourite food was between live grass shrimp, live Asian shore crab, or dead/raw king prawn. The cuttlefish all preferred live grass shrimp the most and did not prefer Asian shore crab and raw king prawn.

Then, a two-drawer device with clear sliding doors was used to show the cuttlefish each option: the preferred and less preferred prey. The doors were marked with symbols which over time the cuttlefish were trained to recognize. One of the drawers would open immediately and contain the dead and less appetizing king prawn. The other drawer, containing the delicious live grass shrimp, would either open after another 10 to 130 seconds, or not open at all. The cuttlefish were placed individually at a distance from the drawers in an aquarium and had to decide. There was the option to, at any time, stop waiting and eat the less preferred food as its door was clear. But, once they approached one chamber, the other would disappear, teaching them that they could only chose one! Would they be willing to wait for the preferred prey, and for how long?

The study set up with the (a) control vs (b) experimental conditions. T represents the delay in seconds (T=∞ did not open, T=0 was immediate, and T>10 was from 10-130 seconds). The immediate access chamber held the less preferred prey, and the delayed chambers had the more preferred prey. (Image Source: Schnell et al.)

Cuttlefish Will Wait

Cuttlefish were found to wait from 50 to 130 seconds for the drawer filled with yummier prey. When the only options were a live shrimp that never opened or a dead shrimp, they chose the dead shrimp.

Cuttlefish are the first invertebrate to show self-control by passing this version of the “marshmallow test”! 

The amazing camouflaging ability of the cuttlefish. (Image Source: Wikimedia Commons, Lakshmi Sawitri.)

This level of self-control was previously only found in long-lived social animals like apes and crows. At some points during the experiment, the cuttlefish would even turn their bodies away from the prey, as if to distract themselves to handle the delay of gratification. Also, the more self-controlled cuttlefish also were faster at learning symbols during the experiments, showing that delay of gratification equates to intelligence (so hold off on that dessert!).

So why were cuttlefish so good at resisting temptation? Although self-control has been shown to help apes and crows for social reasons, cuttlefish live a simpler life without strong social activities. Instead, scientists hypothesize delayed gratification is a way cuttlefish can improve their foraging behaviours. Since cuttlefish camouflage and ambush their prey, self-control could make them more successful foragers as they make smarter decisions like waiting patiently for better prey. If a cuttlefish can outsmart a child, they should be respected and studied for their intelligence as it may hold connections to our own evolution.


3 Responses to “Cuttlefish Pass Intelligence Test by Resisting Temptation”

  1. Sounds like the Cuttlefish is smarter than my own kids!

    Posted by Jason | April 19, 2021, 3:07 pm
  2. Hello
    Excellent read , especially found the camouflaging capabilities the most impressive . Also Interesting was their ability to resist temptation . Good job I also have an affinity to cuddle fish ;-)


    Posted by Chris Boon | April 19, 2021, 2:32 pm

Post a Comment


  • by oceanbites 3 months ago
    Happy Earth Day! Take some time today to do something for the planet and appreciate the ocean, which covers 71% of the Earth’s surface.  #EarthDay   #OceanAppreciation   #Oceanbites   #CoastalVibes   #CoastalRI 
  • by oceanbites 4 months ago
    Not all outdoor science is fieldwork. Some of the best days in the lab can be setting up experiments, especially when you get to do it outdoors. It’s an exciting mix of problem solving, precision, preparation, and teamwork. Here is
  • by oceanbites 5 months ago
    Being on a research cruise is a unique experience with the open water, 12-hour working shifts, and close quarters, but there are some familiar practices too. Here Diana is filtering seawater to gather chlorophyll for analysis, the same process on
  • by oceanbites 6 months ago
    This week for  #WriterWednesday  on  #oceanbites  we are featuring Hannah Collins  @hannahh_irene  Hannah works with marine suspension feeding bivalves and microplastics, investigating whether ingesting microplastics causes changes to the gut microbial community or gut tissues. She hopes to keep working
  • by oceanbites 6 months ago
    Leveling up - did you know that crabs have a larval phase? These are both porcelain crabs, but the one on the right is the earlier stage. It’s massive spine makes it both difficult to eat and quite conspicuous in
  • by oceanbites 7 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring Cierra Braga. Cierra works ultraviolet c (UVC) to discover how this light can be used to combat biofouling, or the growth of living things, on the hulls of ships. Here, you
  • by oceanbites 7 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Elena Gadoutsis  @haysailor  These photos feature her “favorite marine research so far: From surveying tropical coral reefs, photographing dolphins and whales, and growing my own algae to expose it to different
  • by oceanbites 7 months ago
    This week for  #WriterWednesday  on Oceanbites we are featuring Eliza Oldach. According to Ellie, “I study coastal communities, and try to understand the policies and decisions and interactions and adaptations that communities use to navigate an ever-changing world. Most of
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Jiwoon Park with a little photographic help from Ryan Tabata at the University of Hawaii. When asked about her research, Jiwoon wrote “Just like we need vitamins and minerals to stay
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring  @riley_henning  According to Riley, ”I am interested in studying small things that make a big impact in the ocean. Right now for my master's research at the University of San Diego,
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Gabby Stedman. Gabby is interested in interested in understanding how many species of small-bodied animals there are in the deep-sea and where they live so we can better protect them from
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Shawn Wang! Shawn is “an oceanographer that studies ocean conditions of the past. I use everything from microfossils to complex computer models to understand how climate has changed in the past
  • by oceanbites 9 months ago
    Today we are highlighting some of our awesome new authors for  #WriterWednesday  Today we have Daniel Speer! He says, “I am driven to investigate the interface of biology, chemistry, and physics, asking questions about how organisms or biological systems respond
  • by oceanbites 9 months ago
    Here at Oceanbites we love long-term datasets. So much happens in the ocean that sometimes it can be hard to tell if a trend is a part of a natural cycle or actually an anomaly, but as we gather more
  • by oceanbites 10 months ago
    Have you ever seen a lobster molt? Because lobsters have exoskeletons, every time they grow they have to climb out of their old shell, leaving them soft and vulnerable for a few days until their new shell hardens. Young, small
  • by oceanbites 10 months ago
    A lot of zooplankton are translucent, making it much easier to hide from predators. This juvenile mantis shrimp was almost impossible to spot floating in the water, but under a dissecting scope it’s features really come into view. See the
  • by oceanbites 11 months ago
    This is a clump of Dead Man’s Fingers, scientific name Codium fragile. It’s native to the Pacific Ocean and is invasive where I found it on the east coast of the US. It’s a bit velvety, and the coolest thing
  • by oceanbites 11 months ago
    You’ve probably heard of jellyfish, but have you heard of salps? These gelatinous sea creatures band together to form long chains, but they can also fall apart and will wash up onshore like tiny gemstones that squish. Have you seen
  • by oceanbites 12 months ago
    Check out what’s happening on a cool summer research cruise! On the  #neslter  summer transect cruise, we deployed a tow sled called the In Situ Icthyoplankton Imaging System. This can take pictures of gelatinous zooplankton (like jellyfish) that would be
  • by oceanbites 1 year ago
    Did you know horseshoe crabs have more than just two eyes? In these juveniles you can see another set in the middle of the shell. Check out our website to learn about some awesome horseshoe crab research.  #oceanbites   #plankton   #horseshoecrabs 
WP2Social Auto Publish Powered By : XYZScripts.com