Octopus have a pop culture reputation for being intelligent owing to lab maze experiments, but their intelligence isn't well known or defined. They have an average lifespan between 3-6 months to a few years depending on the species.
"Until the 1970s, researchers tried to classify the intellectual abilities of different animals and rank them within a universal intelligence scale with humans at the top. That view crumbled as it became obvious that the abilities of different animals were tuned to the circumstances in which they live.
Rats learn some things slowly and others very rapidly. Just one experience with a novel food that makes them ill will put them off that food for life, even if they only become sick many hours after eating it. It's a useful memory feat for an animal that survives by scavenging. Honey bees remember the location of a flower that is producing nectar after a single visit and with just a few trips will learn at what time of day the nectar flow is at its peak.
Octopuses are not very social so we should not expect their intelligence to show itself in observational learning. [...] True, octopus have huge brains. But they look nothing like the brains of the vertebrates that are so adept at learning. [...] some critics suspect that their intelligence has been grossly exaggerated by anthropomorphising observers-"they watch my every move, therefore they must be curious". On the other hand, because cephalopod behaviour and brain structure are so foreign, others argue that their greatest cognitive feats are probably still being overlooked. " -- https://web.archive.org/web/20120407062518/http://www.fortun...
There is this Netflix movie “my octopus teacher” where the octopus develops rather advanced hunting and camouflage techniques. Like how it knows how to handle sharks or how to build a shell for itself to hunt a particular type of food. That seems quite intelligent and beyond observing humans studiously in labs.
* unscrew the lid of a peanut butter jar to get a treat without training
* hop from one tank to another to prey on the fish in the tank. This was observed quite by accident and not part of an experiment at first. In fact the octopus waited for its human handlers to leave the room before going in for the kill; the incident was caught on camera.
* gently grasp the hand of a friendly human with their tentacles, and squirt water through their siphon at a disliked human
All spontaneously, without training or prompting.
That last bit is particularly interesting to me, because they are recognizable signs of affection and dislike. Octopuses show some semblance of an ability to bond with us, despite having vastly different brains from us.
