| The triune model of the brain is not just a simplification, but one that promotes antiquated biases about human intelligence in how human intelligence differs from non-human intelligence, how intelligence is distributed among humans themselves, and what is essential to defining human intelligence itself. The lizard, small mammal, human distinction maps pretty deceptively onto Aristotle's distinctions between the souls: vegetative (plant), sensitive (animal), and rational (human). So if one is trying to pinpoint the seat of intelligence, it seems to follow that we can ignore the two lower sections of the brain in favor of the higher one. Franz Joseph Gall, the founder of phrenology, himself did that, writing off the cerebellum as relevant only for producing the sexual drive [1]. Scientific theories of self-control which were nothing more than Christian dualist arguments evolved out of Gall's work and argued that intelligence involved suppression of the lower faculties, which provided cover for eugenicist and supremacist arguments throughout the 20th century and still shows up today in popular theories about how the 'limbic system' subverts the rational capacities of individuals and is used to manipulate the masses (Elon loves this theory). Current work funded at the intersection of artificial intelligence and neuroscience still prioritizes the neocortex as the seat of rationality, with some like Jeff Hawkins (Palm founder turned brain scientist) arguing that "intelligence is an algorithm found in the neocortex". Singularity arguments rely in part on the assumption that intelligence in humans is mostly limited by the other parts of the brain, not empowered by them, and that a form of intelligence freed of embodiment will inevitably exterminate those that are embodied by right. The truth is, neglected sub-regions such as the "lizard" cerebellum actually contain the vast majority of neurons, have been shown to have evolved disproportionately larger within early hominins [2], and are theorized to be equally involved in abstract cognition as in bodily manipulation [3]. This is something of a paradigm shift that has only been able to take shape since the late 20th-century (through the work of Jeremy Schmahmann, Peter Strick and others[4]), even though hints of it have been present in the data since it was collected, and that's because of how compelling the triune brain model has been. Research in this direction can directly address mental illnesses such as schizophrenia, but it has to be funded first [5]. [1] https://www.frontiersin.org/articles/10.3389/fnana.2019.0004... [2] https://pubmed.ncbi.nlm.nih.gov/25283776/ [3] https://www.sciencedirect.com/science/article/abs/pii/S03043... [4] https://www.sciencedirect.com/science/article/pii/S089662731... [5] https://www.youtube.com/watch?v=5UUqKuhvTk0 |
In general I think this effect contributes to a lot of "over-debunking". We see way over-simplified, yet very loosely accurate, mid 20th century scientific models like the triune brain, "ontogeny recapitulates phylogeny", the left-brain vs. right-brain, and the idea that differences in language contribute to differences in cognition; and then silly people take these models way too far and use them to justify dubious things; and then they become over-debunked to the point that speaking them aloud immediately ostracizes you as some outdated bigot; while the whole time the models themselves have been reasonably OK high-level starting points for discussion that obviously need revision for any lower-level details.
> The truth is, neglected sub-regions such as the "lizard" cerebellum actually contain the vast majority of neurons, have been shown to have evolved disproportionately larger within early hominins [2], and are theorized to be equally involved in abstract cognition as in bodily manipulation.
The relative number of neurons is not evidence for or against the model, nor the fact that they were larger in early hominins. Showing their involvement in abstract cognition is more interesting, but that's only evidence against the triune brain if you make the exact same mistake that you're criticizing, which is assuming that "abstract cognition" is some high-level uniquely human (or primate) trait. If that exact "abstract cognition" also exists in reptiles and birds (and it appears to), then the fact that the cerebellum contributes to that cognition is not evidence against Triune Brain.