Lobsters are not people

I’ve been getting a tremendous amount of pushback from Jordan Peterson cultists on this video about his ‘lobster’ claims — it’s my most popular (or should I say, unpopular) one yet. I’m seeing a lot of “context!” and “strawman!” and “he really meant to say…” and “you need to watch these 6 hours of videos to understand” kinds of comments. No one cares that his reasoning is flawed or his evidence is weak or wrong, all that matters is that he comes to the conclusion they like — they sound exactly like creationists, or Sam Harris fans. It’s more than a little ugly, and rarely have I seen a more unpleasant collection of people using poorly understood evolutionary justifications for bad science since the last time I looked at an evolutionary psychology article.

Interestingly, though, a colleague independently came to the same conclusions and made very similar arguments. He remains nameless, unfortunately, because no one wants that troop of Peterson’s baboons flinging feces at them, but he did allow his arguments to be posted.

In case you want to use this, here’s an updated write-up. You don’t need to attribute it to me (“a handsome biologist” will do) as I don’t care to engage with you-know-who’s fanbois.

The lobster (i.e., arthropod) and human (i.e., chordate) lineages did not diverge “350 million years ago”. They already existed as separate phyla by the Cambrian (~550 million years ago). Molecular divergence estimates are on the order of 800 million years ago. This error jumps out immediately to anyone with even a basic knowledge of evolutionary history.

All bilatarian animals, including all the non-social ones, have serotonin. Some plants, fungi, and amoebae produce versions of serotonin. Serotonin has several functions — in humans, most of it is found in the gastrointestinal tract. It’s not particularly surprising that lobsters and humans both use serotonin as a neurotransmitter, nor that this would be involved in the neurobiology of any particular behavioural system. There are only so many neurotransmitters, and it is pretty likely that any innate behavioural system is going to evolve to be regulated by the same basic ones. Social hierarchies are almost surely examples of homoplasy across phyla, as is the co-option of serotonin in affecting various behavioural systems.

That anti-depressants “work on lobsters” is not very surprising given the pharmacology of serotonin reuptake inhibitors, which we might expect to work on any neurons that use serotonin as a neurotransmitter. This does not imply that the neural systems of lobsters and humans are especially similar beyond this, however. For one, lobsters don’t even have brains in the same sense as vertebrates. We share some superficial similarities in neural biochemistry (as do pretty much all animals), that’s about all.

Leaving aside the comparison of deeply divergent lineages, there is enormous variability in social structures even among our closest primate relatives. Bonobos have promiscuous sex and matriarchy as part of theirs. The point is that even where hierarchical systems have a presumed genetic basis, this is a rather malleable trait evolutionarily and the specific forms of social hierarchies can be quite different even among species with brains that are extremely similar.

Of course, innate tendencies and genetic hardwiring are at best only part of the story in a complex, cultural primate like humans. Consider language. The physical and neural structures involved in language use are encoded genetically. Which language we learn is cultural. Social behaviour is similar. Yes, there can be genetic underpinnings based on brain chemistry, but how this manifests in a given human society may be greatly dependent on cultural influences. We could also have a culturally-driven system that is enabled because there is a neurological system that can support it. Nature via nurture and nurture via nature.

Moreover, culture can easily override genetic programming in humans — we see examples of this all the time. One of the great things about human brains and human societies is that we can overcome our most base biological impulses through a combination of personal choices and societal norms. In fact, modern society would not function were it not so.

This is an unremarkable example of convergence. Anyone with any competence and basic training in evolutionary biology would come to the same conclusion.


  1. says

    I have to say, I saw the title of this and my stomach dropped. I thought it was a shot at me and my recent post about lobsters and my immediate response was “I didn’t say they were people!”

  2. says

    It makes me sad that I bump into so many people who consider themselves to be pro-science sceptics promoting this kind of nonsense. From the moment I had the misfortune of reading about this lobster thing it seemed pretty clear they were using scientific findings in largely the same way that anti-vaxers and creationists use them, by not understanding them, by making things up, and drawing conclusions that stretch findings in ridiculous ways due to their ignorance of the topic.

  3. says

    On the upside your ‘handsome biologist’, as well as being presumably handsome, gave a response that was understandable even by this one-time (if you’ll excuse the term) ph*s*cs major.

  4. Zeppelin says

    You don’t understand! Peterson actually meant…uh…something I can’t specify, but which isn’t clearly daft and wrong the way a face-value interpretation of his statements is, and which still supports the conclusion I like! You give away your SJW Agenda by not confabulating a sensible argument on his behalf!

  5. Tethys says

    This does not imply that the neural systems of lobsters and humans are especially similar beyond this, however. For one, lobsters don’t even have brains in the same sense as vertebrates.

    I had this same thought, and appreciate the confirmation from the handsome biologist. Lobsters and worms have a very similar neural system with ganglia and a nerve cord, but neither one has a brain like a vertebrate.

  6. John Harshman says

    Lobsters may not be people, but people can be turned into lobsters (or other animals) if they fail to find a mate during the prescribed period. I saw a documentary on this recently.

    One point that needs to be emphasized more is that lobsters are members of a huge clade, Ecdysozoa, most of whose members do not display the behavior being discussed, and humans are members of a less huge but still huge clade, Deuterostomia, most of whose members ditto. In order to make this whole thing homologous and get any lesson about humans from lobsters, you would have to hypothesize convergent loss of the homologous system at hundreds or thousands of intervening nodes. Ignorance of phylogeny has consequences.

  7. dannicoy says

    Yeah was going to comment about this yesterday. I think you are ultimately right about this but the video really doesn’t communicate what you are trying to say as well as it could. A big part of that is to make sure that Peterson is saying what you think Peterson is saying. (I don’t know what Peterson saying because like you I can’t stand Peterson and have seen enough of him to write him off completely).

  8. curbyrdogma says

    I can’t believe that anyone who proclaims themselves as a student of evolution would not only use such an inappropriate model, but apparently ignore all the work done by zoologists, anthropologists and primatologists with regard to social dynamics between the sexes.

    …Not to mention, in order to understand and acknowledge evolution, one must also acknowledge that variation occurs, especially when there is less selective pressure and more environmental/physical/behavioral factors involved (as is the case with humans).

    …But I suppose, in a culture whose attention span is being reduced to ~150 characters, overly simplistic notions are the ticket these days. It’s like the Chicken McNuggets of junk information (or should that be Twitter McNuggets)

  9. Alt-X says

    I thought him and his fanbois didn’t like “identity politics”? Just goes to show, you can be totally wrong, but if you dog whistle enough, the SQW’s will come running, regardless of you’re talking utter crap or not.

  10. DanDare says

    Gees I had never heard of this guy till he was mentioned here. Now on FB I’m being bombarded by what do you think of him isn’t he great remarks.
    Ive only skimmed a few of his vids and he seems to me to be an irritating and arrogant person with poor logic skills. He seems to think all humans are authoritarian like him and only men use you tube.

  11. says

    As someone who knows how much he doesn’t know about biology, my first instinct was to think of elephants and their hierarchies. Then bonobos were mentioned and correct me if I’m wrong, but aren’t both of those closer cousins evolutionarily speaking?
    Seems to me that these “civilized” individuals claim animalistic behaviour is immutable only it it fits their little fantasies of superiority or if it excuses their general shittyness.

  12. Sonja says

    Lobsters are delicious when dropped headfirst in boiling water and then drenched in melted butter, therefore these Peterson fans would be delicious served this way (using his logic).

    OMG — Get out!

  13. monad says

    @5 Tethys: Neither one has a brain homologous to that of a vertebrate, but then neither really does an octopus. It seems to me they’re all convergent concentrated nervous systems that go with cephalization. For some reason, people seem to be ok with calling that a brain in mollusks, but object to it a lot of the time in arthropods. What, exactly, is it that makes the latter less of a brain than the former?

  14. Tethys says

    Sorry to be a nudge, but octopus have 9 brains. (not just a ganglion) A central one and a smaller one in each arm. Cephalization doesn’t really apply to animals that are basically a mobile head, and retain the ability to regrow new body parts should something bite off an arm.

  15. lpetrich says

    Lobsters’ nervous systems are typical of arthropods. Their central nervous system is a pair of cords extending the length of the body along the nose-tail axis on the ventral side. At each segment is a pair of ganglia, one for each cord, and with a connection between them, thus making a ladder shape. The brain is the frontmost ganglion and it is a little before the mouth. Thus, the throat passes through the CNS.

    This does not look very homologous with the vertebrate central nervous system, but there are some homologies in development-control molecules and where they are expressed. So both sorts of nervous system were elaborated in different directions.

  16. monad says

    Tethys, lpetrich, the semantics is what I was looking for, but that doesn’t clear it up for me.
    An octopus has one large central thing – it might be hard to associate with a head, I guess, but it’s easier in squid and from what I’ve read it seems homologous to the brain or cerebral ganglion of a snail – and then smaller things that variously get called brains or ganglia for the arms.
    A lobster has a large thing at the front – sometimes called a brain and sometimes a ganglion but definitely divided into three parts so probably derived from a few fused together – and then smaller things called ganglia for subsequent segments.
    Neither system is homologous to vertebrates but both are important in processing sensory input and controlling behavior; what makes some of them brains and others not?

  17. Tethys says

    IANADB, but the OP seems to be stating that the central nervous system is homologous in animals, while complex brains are convergent. If you look at the basic organs, layout, and structure of molluscs and arthropods they are very similar, though each has very different methods of forming the same basic body plan. (molluscs undergo torsion) At some point everything starts as an egg, and develops poles and cleavage planes. Vertebrates are a sister group to echinoderms, and cousins to molluscs and arthropods. (if I have understood the current science correctly) We have developed wildly divergent body plans over the last 800-600 million years, but the basic building block for a central nervous system was present in LUCA.

    As for homology, I should not have referred to the octopus tentacles as arms. They are in no way homologous to limbs. Placental animals have an entirely different developmental axis and a few extra processes than an octopus. Their common ancestor might be something like a slug, which is basically a tube that eats, but the placement and divisions of that nerve cord is distinct for different animal families.

    Looking at the various ways embryos form, and which parts give rise to particular structures it’s slightly horrifying to contemplate. The homologous structure to an octopus mouth on a human is a navel. The octopus tentacles are homologs to our lips and tongue and nose, they can taste and smell, and are also used to grasp and consume food.


    The ancestors of the arthropods and vertebrates diverged somewhere around 670 million years ago, and was likely a tiny worm called an urbilaterian.

    Wormish yes, but I am in the bilateral symmetry is entirely derived camp. If you look at the other triploblasts you see animals with an odd number of parts and divisions. Positing an Urbilatarian doesn’t address the basic math problem. Neither 3 or 5 is evenly divisible by 2, yet vertebrates have body parts in pairs. You have to go all the way back to the Ordovician echinoderms to see animals that haven’t evolved radial symmetry. They are sessile filter feeders, have five distinct specialized sections, and though they do have a left side and a right side, they do not mirror across a midline. Each section is further divided into three parts vertically from the base to the oral opening.

  18. canuckian says

    I’ve been following the Bill C-16 issue quite closely, and there seems to be a lot of confusion in this thread.

    It does appear that Bill C-16 is a compelled speech law, which would set a dangerous precedent. It’s one thing to censor hate speech, it’s quite another thing to use the law to compel speech.

    And there is a pathway to prison; in particular, should Jordan Peterson willfully refuse to use pronouns, and someone makes a complaint, he will be fined. If he refuses to pay the fine or does not remedy the offense, he can be held in contempt of court and that’s where prison comes in.

    As uncomfortable as I am with Jordan’s position, it is a troubling legal change. And activist lawyers have deliberately misled the public about the potential for prison time.

    Now — the law has not yet been tested, so admittedly, we don’t have any case law, we will have to wait and see. And there’s also confusion about interpretation of the law, both by the legal profession and by the public (the latter gave rise to the Lindsay Shepherd incident at Wilfred Laurier, which played out exactly as Peterson had predicted).

    (Google around if you don’t know the story).

    Also Peterson was sent letters by the University cautioning him that failure to use pronouns might soon be illegal under C-16. They obviously would have consulted with lawyers, as under C-16 the University has vicarious liability. That in and of itself lends some credibility to his claims.

    Peterson participated in the Senate hearings on C-16.

    Someone has taken the time to present some of the more relevant bits; early in the video a lawyer also lays out the potential pathway to prison.


    There of course have been other legal opinions offered, but all of this leaves it to be tested by someone finally bringing a case before a Human Rights Tribunal.

    So please, continue to hammer Peterson on lobsters and failing to respect LGBTQ2+ persons, but on the free speech side, this is a troubling shift we need to monitor. Especially if the political currents change, one worries what speech may be compelled next.

  19. says

    And there is a pathway to prison; in particular, should Jordan Peterson willfully refuse to use pronouns, and someone makes a complaint, he will be fined. If he refuses to pay the fine or does not remedy the offense, he can be held in contempt of court and that’s where prison comes in.

    As uncomfortable as I am with Jordan’s position, it is a troubling legal change. And activist lawyers have deliberately misled the public about the potential for prison time.

    Duh, there is ALWAYS potential prison time. What is misleading is to claim that people will be thrown into jail for accidentally (or not so accidentally) misgendering people.
    Colloquially we understand “thrown into prison for x” to mean that prison is the direct result of x. If I said that my cousin was sent to prison for running a red light and how unfair that was, you would probably agree, because hell that’s harsh. If you then found out that actually he hit an old grandma, fled the scene and later hit the judge in court, you would think that I had been misleading you and you would be correct.
    Being imprisoned* for being held in contempt of court is a separate thing. You can be imprisoned for not showing up in court if you are the witness of a crime, yet you would say it’s dishonest to claim that you get imprisoned for being the witness of a crime.

    *Regardless of that whole nonsense that prison is

  20. Rob Grigjanis says

    canuckian @21:

    It does appear that Bill C-16 is a compelled speech law

    No, it doesn’t appear, because it isn’t. Read the letter from the Canadian Bar Association to a Senate Committee.

    Nothing in the section compels the use or avoidance of particular words in public as long as they are not used in their most “extreme manifestations” with the intention of promoting the “level of abhorrence, delegitimization and rejection” that produces feelings of hatred against identifiable groups.

  21. canuckian says

    Bill C-16 is a compelled speech law. There is no doubt about that. The question is merely about how the law will be interpreted to find guilt, and enforced.

    If you scour the web, lawyers have offered their opinions, and they do not necessarily align with the CBA letter (the CBA is a politicised body as well, so you would do well to add a small dose of caution when reading their letter).

    Here’s the legal opinion of a lawyer from Brown Litigation in Toronto (who also made a submission to the Senate):

    “In summary:

    *Bill C-16 will mandate the use of certain language enforceable by the government;
    *The mandated language may not be consistent with the opinions and beliefs of all persons in Canadian society;
    *It is not clear that one can publicly disavow the mandated language; and,
    *With the passing of Bill C-16, a failure to use the mandated language can result in the power of the state being brought to bear on you, resulting in punishments up to and including imprisonment.

    Given that the Supreme Court of Canada has found compelled speech to be a ‘penalty that is totalitarian and as such alien to the tradition of free nations like Canada even for the repression of the most serious crimes’, it might be appropriate to examine Bill C-16 in greater detail to ensure that it remains consistent with Canadian constitutional principles and Canadian traditions of free expression.”

    I concede, until cases are brought forth, this is all just legal opinion — but that includes the CBA letter. No one actually polled lawyers or judges in Canada.

    But I’m very concerned about free speech, so I met with a lawyer friend who walked me through this — it was his opinion that Peterson’s concerns were correct. This is a fairly high profile lawyer, called to the bar in Canada and the U.S., and if there’s any concern of bias, he’s also gay and very much in favour of transgender rights. He’s also the one who clued me in to the internal political struggle going on within the CBA; at the time we spoke, he was contemplating refusing to sign a new “statement of principles” that will be a requirement for lawyers here in Ontario, but was concerned about the impact on clients.

    The problem with the law is HOW IT WILL BE INTERPRETED, not just by judges, but also by the public. Peterson’s claim was not only that it was a compelled speech law, but that the guidelines the Human Rights Tribunal were to follow were so muddled and confusing, cases would potentially be brought forth in a painful process of sorting out the guidelines (and with the risk of imprisonment as a possibility, this was a real problem, obviously).

    We already have two instances that prove that the public was and is confused — the University of Toronto took a look at Peterson’s claim, and sent him warning letters (and we can assume their lawyers reviewed this, that’s standard practice), and the professor at Wilfred Laurier who interrogated Shepherd also clearly stated that he believed she could be in trouble with the Human Rights Tribunal. You don’t want educators dragged in front of tribunals facing legal action for showing clips from a public broadcaster.

    I will concede, given how much attention this has gotten of late, it may be unlikely we’ll see cases brought.

    But that doesn’t mean that we’re not entering into unprecedented territory, and it’s still very unclear how this will play out as case law stats to build.

    Also, the folks that have responded so far seem pretty confused about the various courts involved. I know probably no one will bother watching it, but you should check out the Senate hearings, you’ll get a glimpse at the “kangaroo court” setting and hear the dissenting opinions.


    Thanks for reading, all the best to you.

  22. says

    and the professor at Wilfred Laurier who interrogated Shepherd also clearly stated that he believed she could be in trouble with the Human Rights Tribunal. You don’t want educators dragged in front of tribunals facing legal action for showing clips from a public broadcaster.

    And here’s where all assumptions of good faith go out of the window.
    Shepherd got into trouble for creating a hostile climate, not because she “showed a clip”, but because she showed a clip in a class on academic writing, which means that she rode her personal hobby horse instead of doing what she was paid to do, without presenting any context or indeed having any educational goal here (as has already been mentioned probably because this was absolutely way outside of her assigned teaching responsibilities and expertise). In short, she abused her position of power to create a hostile climate.
    If a mathematics professor showed a clip where someone is arguing that gay men are all child rapists in his analysis class, should that professor face some action?
    Oh, and as a teacher, am I allowed to call my students by any odd name I like? Because obviously saying that I must call a student named Mike “Mike” and not “Kiki” because Mike is silly is compelled speech, right?

  23. Dunc says

    If he refuses to pay the fine or does not remedy the offense, he can be held in contempt of court and that’s where prison comes in.

    And if he resists the attempt to take him to prison violently enough, he may be shot! Oh my god, he could be executed!

    This is a thoroughly ridiculous argument.

  24. canuckian says

    Re: contempt of court, if you can’t see this is a way to smuggle in a prison sentence for those that do not conform, I can’t make you see it. But even if you merely don’t have assets to pay the fine, you will go to jail.

    And what happens if this law is on the books, providing precedence, and the climate moves to the right? What kind of speech will censored or compelled then?

    The slippery slope argument actually works in law because it is built on precedents.

    Which get reinterpreted over time.

    That’s why there are some fundamental principles we maintain, like free speech, so neither side can abuse their power.

    As for Shepherd creating a hostile environment, if you think playing a clip from the debate which was played on a public broadcaster, in a class where they are studying language, and in which she pointed out she thought Peterson was WRONG, and NO STUDENT actually complained… oof.

    No you can’t call students names. If you do, you can be reprimanded or fired.

    But the threat of prison time should be not even close to a possibility.

    Anyway, I have already conceded there are lots of grey areas — but that several legal experts agree with Peterson’s understanding of the law points out that his concerns had some validity.

    I know I have failed to convince you, but your mind is made up. I hope I’m wrong and this law won’t be abused or expanded. If it is, we know we can’t count on you.