The Geniuses of The Ocean Octopuses have enormous brains for invertebrates, but not that large when compared to vertebrates. Despite this, they have distinct personalities, showing tendencies to be either more avoidant or more assertive. They can recognize and even show preferences for individual people – an intriguing ability, because usually only social creatures can do this, whereas octopuses tend to be solitary creatures who are highly aggressive with one another.They are also adept at manipulating their environment, and can even use tools. In one case, at Santa Monica Pier Aquarium in California, staff discovered that a puddle on the floor next to a tank with an octopus in it was a result of the octopus disassembling a water-recycling valve.Another story about a clever octopus in captivity is that of ‘Inky,’ an octopus who lived in the National Aquarium in Napier, New Zealand. One night his enclosure lid was left slightly ajar. The next morning, his keepers discovered that Inky had vanished – he’d managed to squeeze his way out of his enclosure and crawl across the floor, sliding through a 15cm (6in) wide drain pipe that led back to the sea: a real life Finding Nemo moment!Octopuses in captivity have figured out how to twist off jar lids and solve simple puzzles. One theory about their intelligence is that ‘they got smart because they got soft’ – they have had to use their brains to survive because they have no hard outer shell or other protective features with which to fend off predators.So, are octopuses like humans in regard to intelligence? Our last common ancestor, thought to have resembled a flattened worm, existed over 600 million years ago. However, an incredible commonality exists between humans and octopuses – they have developed high-resolution camera-like eyes, just as we have. This is an incredible coincidence of evolution, because it seems that this particular adaptation was arrived at twice, totally independently.Octopuses seem to have both short-term and long-term memories, just as we humans do. They also appear to experience similar sleep states. While it’s clear that octopuses are highly intelligent creatures, it’s hard to say how closely they compare to human intelligence. Because they developed over many millions of years along a completely different line from mammals, their kind of intelligence is very different to ours – yet another reason why they seem like aliens to us!