I've finished the book and overall find it to be quite good. I'll just sum up my reaction to the last few chapters.
One of the chapters is titled "When Failures of Belief Revision Are Less than Motivated Reasoning or Sloppy Reasoning." Goel writes:
In short, what I'm suggesting is that some false beliefs are resistant to rational evidence because the motivating desire is not a cognitive desire. It is a desire propped up by instinctual (and other) low-level subcortical systems....
This is one of the most important ideas in the book and is a good starting point for examining the current political polarization within many Western countries.
The next chapter, "Global Belief Revision is Constrained by Neural Maturation," describes how neural systems start out relatively fluid, but once they mature they become less flexible:
If the receptive window of opportunity is missed, no amount of sensory stimulation is going to change the organization of the mature visual or auditory cortex. Once this window passes, the organization of the primary cortex and associated subcortical structures is largely fixed. They cannot be reorganized or repurposed to deal with a radically different environment....These subconscious perceptual biases – even though they may be an accidental feature of the environment – will feed into the In-Group/Out-Group system and infiltrate up into presuppositions and belief systems.
The consequence is this:
If it is indeed the case that the scope for belief revision is limited after neural maturation of the association cortex, it has interesting implications for our standard cognitive and social science Platonic models of mind, where rationality is divorced from biology. Even if in some ideal world the machinery of reason may allow for extensive and perpetual belief revision, the actual biology that supports the machinery may not.
So, in addition to interplay between the different components of a mature brain, neural maturation separately limits change as people age. Goel notes that, according to a survey, young people are generally more receptive to the idea of anthropogenic climate change than older people. This may be because the older people grew up before global warming was a recognized phenomenon, and for this reason their brains do not recognize it as a significant risk.
Goel also includes an interesting personal anecdote that serves as an example. He was born to Indian parents in India. The family moved to Canada when he was young, and he grew up there. Later, when his family returned to India to visit relatives, he found that Indians all looked the same to him, and he could hardly distinguish them. I find this highly amusing, because, in politically correct circles, Goel would typically be described as a racist because of his visual insensitivity to Indians – in this case his own relatives. Obviously, this kind of political correctness is based entirely on biological ignorance. I could relate to this example, because I moved from the U.K. to the U.S. when I was seven and think that it affected my mental development. Since then, I have lived in eight different states, and I always notice that people who have lived only in one location, particularly if it is rural, tend to have very limited worldviews. Education may make a difference, but you can see how the environment affects brain development.
In the final chapter, Goel points out that his tethering model is different from the standard social science and cognitive model, which emphasizes rationality, and the standard evolutionary psychology modularity model, which emphasizes biology and evolution and minimizes the role of reason. I am inclined to agree with his model, because the role of reason is vastly exaggerated in economics and other social sciences, and this significantly reduces its usefulness for public policy. I am sympathetic with the biological/evolutionary approach, but agree with Goel in the sense that some room must be left for reason and its acceptance as a real phenomenon. What I like about Goel's model is that it allows one to speak intelligently about the mountains of cognitive errors that one confronts on a daily basis. As I've been saying, when trapped between right-wing ideology and political correctness, it is disturbing that no one before now has stepped up to address the intense cognitive dissonance that it can cause. This book is the first one that I've read that provides a usable model for that task. It is probably no coincidence that the book was written by a Canadian, who may be less worried about being fired for his views than his cowering American counterparts.
My only criticism of the book is that the subtitle is a little misleading. The main example about food concerns Goel's admission that he is unable to stop eating chocolate cake even though he knows that it makes him overweight and unhealthy. The main example about sex concerns John Edwards, the politician who had an affair while he was running for the Democratic presidential nomination and his wife was dying from cancer. Goel thinks that Edwards was stupid to have an affair at that time. The examples from politics include the first impeachment trial of Donald Trump and the fishing crisis in the Canadian Maritime provinces. Although I found the examples useful, I initially thought from the subtitle that food, sex and politics would be the central themes of the book, but, as it turned out, they were merely a few examples used to explain his theory. One could write volumes on the subtitle alone, and it is probably just as well that Goel remained focused on his model. Perhaps Goel or his publisher thought that "Sex" on the front cover would increase sales. I don't think it has so far.