Octopuses, Ecstasy, and the Evolution of Intelligence

According to science, octopuses (it’s not octopi) respond to MDMA, or ecstasy as it is commonly known, in a similar manner to humans. Neuroscientists at John Hopkins University submerged five octopuses in MDMA-laced water, where the cephalopods imbibed the drug through their gills, before releasing them into a tank with a novel object at one end (a Chewbacca figurine in this instance) and a trapped male octopus at the other. While octopuses are normally solitary hermits, and preferred to check out the toy in control trials, they became much friendlier in the experimental condition, and made friends with the other octopus, by touching arms and showing their undersides, where their beaks are, which they very rarely do when sober. So, if you were wondering if octopuses like molly, you have your answer: they do. Hooray.

Except that, despite making headlines around the world, this is merely a preliminary study, with a sample size you can count on one hand. Only one species of octopus was tested, and the study was not counterbalanced: the experimental condition always occurred after the control (being submerged in salt water before exploring the tank), meaning that we can’t really say if the octopuses were responding to the ecstasy or were simply more familiar with the environment and thus more social. The study’s authors are frank about these limitations, and hope that they lead to more research in the area to see how other cephalopods respond to psychedelics like MDMA and what this can tell us about the evolution of intelligence. This is why they gave molly to the octopuses in the first place.

Now, let’s back up. Any discussion of octopuses and consciousness should begin with Jacques Cousteau, the French undersea explorer and scientist and Wes Anderson reference who was the first, along with his team of divers, to really spend time with and film the creatures in the wild. He documented his experiences in the 1973 book Octopus and Squid: The Soft Intelligenceand in numerous television programs. While the behaviours he reported are not the result of scientific experiments, they are nonetheless remarkable. He filmed an octopus stealing fish from a fisherman’s net, and another opening a jar of food. He reported that some of the animals would greet his team and ride on their backs, while others were shy and avoided contact.

Image Courtesy of Bernard DUPONT via Wikimedia Images © 2009, some rights reserved

Octopuses, as Cousteau no doubt found out, are notoriously difficult to study. It is costly and time-consuming to track them down for observation in the wild, with the few research teams that have done so requiring rotating teams of divers so as to not lose track of their subjects. They are not easy to keep in the lab either, as they are sensitive to water and light conditions, with one going so far as to short-circuit the light above his enclosure by squirting a jet of water at it because it was too bright, not to mention that they are devilishly crafty escape artists. One of the octopuses kept at the National Aquarium of New Zealand, Inky, executed an elaborate escape in 2015 by breaking out of his tank and crawling across the floor to an open drain that led to the ocean, Finding Nemostyle. Needless to say, Inky has not been seen since.

Nevertheless, despite these difficulties (which one could argue are a result of their intelligence), many fascinating things have been discovered about cephalopods in the years between The Soft Intelligence and this most recent octopus-ecstasy investigation. Firstly, they have a complex nervous system containing around 500 million neurons, which might not seem like much considering that humans have about 86 billion neurons in our nervous systems, but is absolutely extraordinary considering that it is the most of any invertebrate species, and 500 times more than the runner up, honeybees, who only have around a million. This uniqueness is recognized legally, as the common octopus is the only invertebrate species protected by the 1986 Animals (Scientific Procedures) Act, which regulates animal testing in the U.K. Furthermore, their complex nervous systems are not organized like other complex nervous systems: two thirds of an octopus’ neurons are spread throughout its eight arms, with the remaining third in the brain. This allows each arm to act semi-autonomously, and the arms are as much responsible for taste as they are for touch. They are capable of completing tasks that tend to stump animals with similar numbers of neurons, such as opening jars, executing complex escapes, and recognizing faces. Octopuses are so good at recognizing and remembering faces that in one study they could distinguish between people wearing identical uniforms.

Mastering these tasks, experiment after experiment, inevitably raises the question of intelligence. Comparative psychology has been chipping away at human uniqueness for decades, with traits once thought to be unique to humans, such as tool use, social learning or an understanding of time and planning, to name a few, being found in more and more animal species. The discovery of the seeming ubiquity of these traits follows a predictable pattern: first a trait believed to be exclusively human is discovered in apes, then in monkeys, then in other mammals, then birds, and so on, working backwards through the evolutionary tree. This paradigm has served the field well, but it is based on the assumption that intelligence evolved once, that there is one evolutionary path of increasingly complex minds that leads from invertebrates to vertebrates to mammals to us, as it were. The intelligence of octopuses disrupts this narrative, as our closest common ancestor lived 600 million years ago, and was probably an ocean-dwelling worm-like creature. Thus, the intelligence of octopuses evolved independently of that of humans, and while it is not as developed as ours, its evolutionary distance from us seriously challenges that we are the endpoint of the evolution of intelligence. It seems as though nature built minds twice, once in the depths of the ocean, and another, perhaps more successful time, in the plains of Africa.

Which brings us back to the results of the octopus-ecstasy experiment. While it is merely an exploratory study, and the results seem trivial (octopuses aren’t going to undersea raves as far as I am aware), its implications are potentially vast, as they comprise another chip in the wall between human and animal intelligence, a barrier that comparative psychology has been steadily chipping away at since 1960s at least, when Jane Goodall first observed complex social behaviour in chimpanzees. The long-term goal of the study’s authors is to list the fundamental building blocks of complex behaviours, such as specific neurotransmitters or synapses, that are needed to produce intelligence in some form. Ecstasy plays a role in this goal by modifying behaviour chemically: the drug works by bonding to serotonin transporters in the brain, facilitating the release of excess serotonin, which produces the emotional and behavioural changes the drug is known for. Both octopus and human brains use serotonin to send signals between neurons, but the octopus serotonin transporter is only 50% similarto the human one. Ecstasy bonds to both, though, and produces similar chemical and behavioural effects, which is remarkable given all of the differences between our nervous systems. Further research will determine if this is one of the fundamental building blocks they are looking for, but it is nonetheless exciting to find a similarity between two intelligent but distant species.

Cousteau noted, in The Soft Intelligence, that “Scientists, although they concede that the octopus has a memory and that it learns quickly, do not use the word ‘intelligence’ in describing it.” While he wrote this 45 years ago, the consensus has not changed much. Despite the growing body of research since 1973 demonstrating the intelligence of many animal species, we remain reluctant to call a spade a spade, preferring instead to insist on our uniqueness and thus separate ourselves from the rest of the animal kingdom. And while we are unique in the advanced level of our intelligence, our advanced intelligence did not arrive fully formed. It came to us by way of many simpler intelligences which are still all around us today, out in the world to encourage us to explore and ponder the origins of our own complex minds. There are no binaries in evolution, no on-off switches to activate abilities in an organism that did not exist in simpler forms in its ancestors. We are no exception to this rule, and we would do well by letting this humble us.



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