It's a decent compilation of evolutionary facts that the author tries to explain with the theory of the "intelligence paradox" where high IQ people act in evolutionary novel terms.
I knew most of these facts and interpretations, and they are uncontested amongst people familiar with evolutionary explanations of human behavior.
But this book could have been shorter, even 5 pages in the form of a condensed scientific review could have been enough.
Also, he lost me in a few sections and in the last chapter where he tried to apply his theory to political systems...
For more, see the excerpts I shared during reading:
"How polygynous members of a species are in general correlates with the extent of sexual dimorphism in size (the average size difference between the male and the female). The more sexually dimorphic the species (where the males are bigger than the females), the more polygynous the species."
"This is either because males of polygynous species become larger in order to compete with other males and monopolize females,4 or because females of polygynous species become smaller in order to mature early and start mating.5 Sexual selection can also create sexual dimorphism in size, if women prefer taller men as mates and/or if men prefer shorter women as mates."
"... what is indisputable is the positive association between the degree of polygyny and the degree of sexual dimorphism in size, both across species and across human societies. Thus strictly monogamous gibbons are sexually monomorphic (males and females are about the same size), whereas highly polygynous gorillas are equally highly sexually dimorphic in size."
"the average human male is only 17% heavier than the average human female.10 So, on this scale, humans are mildly polygynous, not as polygynous as gorillas (let alone southern elephant seals), but not strictly monogamous like gibbons either."
"a major determinant of the level of polygyny in society [is] income inequality. The more unequal the income distribution, the more polygynous the society...it makes more economic sense for women to share a wealthy man than to monopolize a poor man. In the words of George Bernard Shaw “The maternal instinct leads a woman to prefer a tenth share in a first rate man to the exclusive possession of a third rate one.”"
"much of what we now call interpersonal crime today, such as murder, assault, robbery, and theft, were probably routine means of competition among men for resources and mates. This is how men likely competed for resources and mating opportunities for much of human evolutionary history."
"Less intelligent individuals are significantly more likely to want to become parents, and more intelligent individuals are significantly more likely to want to remain voluntarily childless."
"Among women, childhood general intelligence significantly decreases the number of children they have had in their lifetimes. Among men, it does not. While the effect of childhood general intelligence on women's fertility is consistent with the prediction of the Intelligence Paradox, the lack of the same effect among men is inconsistent with it."
"It is not clear to me why more intelligent men, who wanted fewer children than less intelligent men at the start of their reproductive careers, do not actually have fewer children. This is in sharp contrast to more intelligent women who wanted fewer children and in fact do have fewer children than less intelligent women."
"[Is a demanding career a factor? ] But this is not the case. Only childhood intelligence, not educational achievement or earnings, decreases the number of children women have. Contrary to popular belief, more educated women and women with more demanding careers do not have fewer children and are not more likely to remain childless."
"Another possibility is that women find intelligent men more attractive as mates. The evolutionary psychologist Geoffrey F. Miller has consistently argued that women preferentially select men with higher levels of intelligence to mate with.
[My note: Lack of more intelligent men for these intelligent women, who as a consequence can't fulfil their hypergamy in regard to intelligence]"
"Among both men and women, number of siblings significantly increases the number of children. Since the number of siblings (plus one) is the same as the number of children that their parents had, this means that fertility—the total number of children individuals have—is highly heritable. The more children your parents have had (and hence the more siblings you have), the more children you have yourself."
"Genes determine about 80% of the variance in adult [general] intelligence. On average, more intelligent parents beget more intelligent children. And the genes that influence general intelligence are thought to be located on the X chromosomes. ... It means that boys inherit their general intelligence from their mothers only, while girls inherit their general intelligence from both their mothers and their fathers."
"So women influence the general intelligence of future generations very strongly, through their sons and through their paternal granddaughters. If more intelligent women have fewer children and are more likely to remain childless, then one potential consequence is that the average level of general intelligence in society may decline over time."
"the Lynn-Flynn effect, during the 20th century ... secular rise in IQ due to better infant and child nutrition and health. ... This effect is already halted in advanced industrial nations."
"There is strong evidence to suggest that the Lynn-Flynn Effect was only a 20th-century phenomenon. It appears to have ended at the end of the 20th century in the most advanced industrial nations. Studies suggest that the average level of intelligence has begun to decline at the beginning of the 21st century in such advanced industrial nations as Australia, Denmark, Norway, and the United Kingdom."