Man cannot live by serotonin alone — but it helps

From Climate Scepticism

By John Ridgway

Jordan Peterson is a celebrity intellectual who tends to sow division wherever and whenever he shows up. I don’t know whether he likes it that way, but it certainly doesn’t seem to have substantially harmed his celebrity status. He has outspoken views on many of the subjects that tend to divide us, so I suppose one would have to accept his notoriety as an occupational hazard and leave it at that. But there is one source of his notoriety that tends to crop up more often than not and so it is perhaps worth spending a little of our time to delve a tad deeper. Yes folks, I want to talk about lobsters.

It all started when Peterson wrote a book aimed at encouraging young males to take more personal responsibility, and he chose to draw parallels between lobster neurochemistry and that of mankind. Specifically, he pointed out the role that serotonin plays in helping lobsters establish hierarchy within groups. The point he wanted to make was that, despite our evolutionary remoteness from the lobster, the same neurotransmitter could be found in the human brain performing a similar role. This observation led to a great deal of mockery, somewhat akin to that encountered in early debates between Darwinians and theologians, in which the latter tried to put the scientists on the back foot using the descended-from-monkey straw man. His lobster thesis seemed an easy target for ridicule, and so ridicule is what it has received. Surely, Peterson was being simplistic at best and ill-informed at worst. You can’t base a strategy for personal improvement upon an understanding of lobster psychology.

Peterson sticks by his remarks but so does the army of critics who cite his lobster references as clear proof that he is a pseudo-intellectual who appeals only to your average, cognitively challenged, right-wing conspiracy theorist. Neuroscientists, many of whom I suspect just don’t like what Peterson stands for, have been queuing up to attack Peterson’s be-more-lobster entreaty, on the basis that he is plain wrong about the lobster and that you just can’t draw any parallels with the much more complex neurochemistry of the human brain. But are they being entirely fair in their criticism?

The sort of attention Peterson has attracted can be found in an article published on The Conversation website by Dr Leonor Gonçalves, Research Associate in Neuroscience, Physiology and Pharmacology, UCL. The article emphasises the vast difference in complexity existing between lobster and human neurobiology before pointing out what seems to be a glaring hole in Peterson’s argument:

While lower levels of serotonin are associated with decreased levels of aggression in vertebrates like the lobster, the opposite is true in humans. This happens because low levels of serotonin in the brain make communication between the amygdala and the frontal lobes weaker, making it more difficult to control emotional responses to anger. So not only does it seem unlikely that low levels of serotonin would make humans settle in at the bottom of a hierarchy, it goes to show that lobsters and humans are just not a great comparison.

This seems quite damning. However, Dr Gonçalves misses out an all-important word when referring to levels of aggression in humans – and that word is ‘impulsive’. The real picture is provided for you by Professor Robert Sapolsky of Stanford University, in his book ‘Behave: The biology of humans at our best and worst’:

Starting with a 1979 study, low levels of serotonin in the brain were shown to be associated with elevated levels of human aggression, with end points ranging from psychological measures of hostility to overt violence. A similar serotonin/aggression relationship was observed in other mammals and, remarkably, even crickets, molluscs, and crustaceans. As work continued, an important qualifier emerged. Low serotonin [in humans] didn’t predict premeditated, instrumental violence. It predicted impulsive aggression, as well as cognitive impulsivity.

Whilst Dr Gonçalves may be right with regard to serotonin and impulsive aggression, it isn’t impulsive aggression that Peterson is referring to in lobsters. As far as premeditated, instrumental aggression is concerned (the sort of aggression that might get you promoted within a hierarchy), there is nothing in the research that Dr Gonçalves cites to suggest that serotonin levels correlate any differently in humans than they do in lobsters, despite the massive differences in complexity. Besides which, levels of aggression are a bit of a red herring. The important issue instead is how impulsivity in its many forms can be controlled by serotonin. If anything is designed to get in the way of social advancement, it would be impulsivity.

Based upon her misunderstanding of the link between serotonin and aggression, Dr Gonçalves speculates that it is unlikely ‘that low levels of serotonin would make humans settle in at the bottom of a hierarchy’. The reality is that there are many reasons why low levels may result in such settlement and one doesn’t have to look far for the research that confirms this. Take, for example, research conducted by Dr Anna Ziomkiewicz of the Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland, which states:

Serotonin was found to directly support dominance structure in primate groups. Studies conducted in vervet monkeys (Cercopithecusaethiops) demonstrated that alpha-male individuals had higher levels of blood and brain serotonin that decreased when dominant position was lost (Raleigh 1984).

Which, of course, is exactly what Peterson has said regarding the much less complicated lobster. That said, the relationship between dominance, serotonin and aggression for the vervet monkey is a lot more involved than for your average crustacean:

The serotoninergic system was demonstrated to support all of these behaviors, i.e., aggression, cooperation, and affiliation, however not in a simple manner. In vervet monkeys, subordinate group members treated with serotonin enhancers achieved dominance by first increasing affiliative behavior toward group members and creating a support group. During this period, aggressive behavior significantly decreased, while affiliative behavior (approaching and grooming) was significantly increased. Only after coalitions with other individuals were established dominant individuals engaged in aggressive encounters with conspecifics (Raleigh et al. 1991).

One should not be surprised to see such complexity. If there is one thing to appreciate regarding the actions of neurotransmitters it is that their importance is highly context-specific and they can effect quite different behaviours depending upon environmental factors and the machinations of other neurotransmitters. Those who criticise Peterson with his lobster observations seem to assume that he is unaware of such complexities and is attempting a trite comparison. I don’t see it that way. I would rather assume that a Harvard professor fully understands how complexity in life-form and social structure complicates the relevance of the serotoninergic system but might still seek to point out that even species that are vastly separated on the evolutionary tree nevertheless can still both have a serotoninergic system that plays a role in establishing hierarchies.

I started out this essay by pointing out that Peterson is a divisive character, and I’m afraid that when divisive characters hold forth on subjects you will find that the divided are quick to judge. The easiest approach to take by those who disagree with Peterson’s conclusions is to characterise his arguments as lacking academic rigour. A lobstergate scandal fits this bill nicely. If you get enough neuroscientists posting critiques on websites such as The Conversation, scoffing at Peterson’s science, then the man can be taken down. However, for that to work effectively, the criticisms themselves have to be based upon a sound understanding. Failing to understand the important difference between aggression and impulsive aggression, and failing to appreciate the many ways in which serotonin is implicated in social behaviours does not benefit Peterson’s naysayers. Furthermore, it is no more appropriate to suggest that Peterson is saying we are all basically just lobsters than it was for Darwin’s detractors to suggest he was saying we are all basically descended from monkeys. In both cases the edict seems to be that one should never let a good straw man go to waste.