He writes,

many of the new-fangled types of intelligence that have become popular recently…boil down to general intelligence plus some combination of the Big Five personality traits. Social intelligence…seems rather well predicted by a combination of general intelligence and extraversion, plus agreeableness (when empathy pays) or disagreeableness (when exploitation pays). People with autism have only somewhat reduced average intelligence, but they typically have severely reduced extraversion and agreeableness…the capacities for perceiving and understanding emotions correlate strongly with general intelligence, and emotional self-management correlates strongly with conscientiousness and stability…short-term creative intelligence is basically general intelligence plus openness, while long-term creative achievement is also predicted by conscientiousness (hard work and ambition) and extraversion (active surgency and social networking).

More excerpts below.

Can you recommend other treatments of the Big Five personality traits, so that I will not have to recommend Spent?Tyler Cowen’s forthcoming book focuses on what Cowen calls autistic tendencies. From Miller’s perspective, Cowen would be describing people with low extraversion and low agreeableness, but with enough general intelligence, conscientiousness, and emotional stability to function, and indeed to escape the label of autism. We figure out coping mechanisms that allow us to thrive despite our low extraversion and low agreeableness. We have high openness, and thus we are creative. Many of us make bad first impressions, but some of us are more likable when you get to know us.

I should note that although he spends a lot of his book lamenting the effort that we put into signaling traits when instead we could just wear trait scores tattooed on our foreheads, I do not believe Miller ever tells us his own traits. Instead, he presents several paragraphs of signals, most of which seem to be focused on showing off his general intelligence and his openness. I suspect that Miller is one of us disagreeable introverts. I suspect that Miller would not be easy for me to like, even after I got to know him. Maybe not enough emotional stability for my taste.

Miller argues that a just as the peacock evolved a long tail in order to display biological fitness to potential mates, we have evolved a complex consumer society in order to display where we are (or would like to pretend to be) on our six personality traits

through certain kinds of credentials, jobs, goods and services

The six traits are general intelligence (IQ), openness (as opposed to rejecting ideas that threaten one’s religion or ideology), conscientiousness (as opposed to lacking commitment and self-discipline), agreeableness (as opposed to questioning authority figures and popular beliefs), stability (as opposed to being driven by strong mood swings), and extraversion (as opposed to having strong needs for solitary reflection).

All six dimensions are also genetically heritable…these differences are predicted at least moderately by genetic differences, and not just by family upbringing or random effects during development. They are fairly stable across the life course…They are all salient to other people during normal social interaction, and are assessed fairly accurately, if unconsciously, even with the first few minutes of interaction with a stranger.

Miller.’s reductionism treats our ideological posturing as a reflection of the traits we are signaling.

Each individual’s ideology (religious, political, and philosophical beliefs) can be viewed not as his editorial content but as his ad campaign

So, if I were more agreeable, I would just “go green,” rather than questioning the idea.

In any species of social primate, a higher-status animal is simply one who is looked at and groomed more often by others…and who is solicited more often as a friend, ally, or mate. (Robin Dunbar has shown that we humans use verbal grooming–talking–instead of physical grooming to ingratiate ourselves with higher-status individuals.)

Throughout the book, Miller tries to draw a contrast between buying things because we enjoy them and buying things to show off. But sometimes I worry that the distinction simply boils down to saying “I would buy X myself, so when you buy X it is because you enjoy it. But I would never buy Y, so when you buy Y it is because you need to show some trait.”

On taking Latin in high school, Miller writes,

You know some costly signaling is giong on when thousands of teenagers spend three years each learning a long-dead language just so they’ll score better on an IQ test [the SAT] that pretends it’s not an IQ test, so they can spend four more years and a hundred thousand dollars to get a college degree that pretends it’s not an IQ guarantee.

Back to ideology as a signaling mechanism.

an entire American university can suddenly act as if it cared deeply about the political fate of a country that it virtually ignored the year before. The consensually accepted way to display agreeableness simply shifted, capriciously and quickly, from one political issue to another.

…Trying to convince someone to switch from Green to Libertarian on the basis of rational arguments and empirical evidence is as futile as trying to change someone’s inherited personality type by these means.

Miller’s recommendations for political and social change are rather novel. For example, he thinks that more homogeneous communities could reduce the need to use consumer goods as signals.

governments should give people the freedom to create local housing communities with the power to sustain their own social norms, as long as a few basic human rights are respected…the government still has a crucial role to play in protecting the oppressed or vulnerable from the tyranny of the majority, even within the most radical of the local communities. However, if the local majority cannot impose some distinctive social norms on our forms of trait signaling, conspicuous consumption will be the only game in town.

…we need the freedom to live assortatively with like-minded people, and to establish a much wider variety of local communities with their own values and norms, sustained by their own forms of praise and punishment.