Octopuses and their relatives are a new animal welfare frontier Premium

Cephalopod intelligence, behavior, and ethical treatment explored by a comparative psychologist in a thought-provoking article.

We named him Squirt – not because he was the smallest of the 16 cuttlefish in the pool, but because anyone with the audacity to scoop him into a separate tank to study him was likely to get soaked. Squirt had notoriously accurate aim.

As a comparative psychologist, I’m used to assaults from my experimental subjects. I’ve been stung by bees, pinched by crayfish and battered by indignant pigeons. But, somehow, with Squirt it felt different. As he eyed us with his W-shaped pupils, he seemed clearly to be plotting against us.

Of course, I’m being anthropomorphic. Science does not yet have the tools to confirm whether cuttlefish have emotional states, or whether they are capable of conscious experience, much less sinister plots. But there’s undeniably something special about cephalopods – the class of ocean-dwelling invertebrates that includes cuttlefish, squid and octopus.

As researchers learn more about cehpalopods’ cognitive skills, there are calls to treat them in ways better aligned with their level of intelligence. California and Washington state both approved bans on octopus farming in 2024. Hawaii is considering similar action, and a ban on farming octopus or importing farmed octopus meat has been introduced in Congress. A planned octopus farm in Spain’s Canary Islands is attracting opposition from scientists and animal welfare advocates.

Critics offer many arguments against raising octopuses for food, including possible releases of waste, antibiotics or pathogens from aquaculture facilities. But as a psychologist, I see intelligence as the most intriguing part of the equation. Just how smart are cephalopods, really? After all, it’s legal to farm chickens and cows. Is an octopus smarter than, say, a turkey?

Cephalopods are a broad class of molluscs that includes the coleoids – cuttlefish, octopus and squid – as well as the chambered nautilus. Coleoids range in size from adult squid only a few millimetres long (Idiosepius) to the largest living invertebrates, the giant squid (Architeuthis) and colossal squid (Mesonychoteuthis), which can grow to over 40 feet in length and weigh over 450 kg.

Some of these species live alone in the nearly featureless darkness of the deep ocean; others live socially on active, sunny coral reefs. Many are skilled hunters, but some feed passively on floating debris. Because of this enormous diversity, the size and complexity of cephalopod brains and behaviours also varies tremendously.