In Global Inequality as a Consequence of Human Diversity, Tatu Vanhanen’s stated purpose is to use empirical evidence of differences in human diversity to explain some global inequality. While other authors have focused on political and environmental factors to explain differing global living standards, Vanhanen examines human diversity that may be attributed to evolutionary differences. This brief, easy-to-read book is an extension of several previous works by the author and his colleague Richard Lynn using updated data.
The best parts of this book are Chapters 1, 2, and 5. Chapters 1 and 2 extensively review the literature on global economic inequalities. All the studies presented either give a detailed description of these inequalities or explain differences in living conditions as functions of political or environmental factors. Some authors give policy prescriptions that, if taken, might even out these inequalities. None of the works reviewed lists differences in human diversity as a causal factor in global inequality. Chapter 5 is a survey of the overview of events and conditions in different nations. Together, these three chapters give the reader a good understanding of global differences in living conditions and the many different possible explanations for these differences.
The other parts of the book are more problematic. In Chapter 3, Vanhanen identifies six different indicators of global inequality in 178 countries: purchasing power parity / gross national income (PPP/GNI) per capita in 2012; tertiary education in 2010; under-5 mortality per 1,000 live births in 2010; life expectancy in 2010; a measure of sanitation in 2010; and an author-created 2010 index of democratization. He correlates each of these variables with an average of national IQ data from 2006 and 2012, and he combines the six variables into an index of global inequality (IGI). The author views all six variables as equally important; thus, these variables have equal weights in the IGI. He hypothesizes that countries with a high national IQ, which he uses as a proxy for evolved human diversity, will have a low IGI and that higher IQs are associated with higher incomes, better education, less infant mortality, higher life expectancies, better sanitation, and more democratization. He proposes that higher average intelligence will lead to better socioeconomic living conditions and less poverty, but, unlike other analysts, he never seriously entertains the confounding of cause and effect.
Part 2 of the book is, purportedly, a test of this hypothesis. Vanhanen deploys correlation analysis and regression analysis to criticize the prevailing view that global inequality is primarily a function of environmental and political circumstance, and that genetic differences between populations are not meaningful explanatory variables. He contends that inequality in the human condition is caused by evolved diversity, where nations with higher average intelligence are better able to survive a struggle— and he seems to be thinking only of an external struggle—for scarce resources. (He does not explain why any nation would have evolved to succumb in such a struggle.) Noting, with some justification, that past government policies based on the prevailing view and aimed at reducing intergroup differences in inequality have not been particularly effective, Vanhanen argues, oddly, that ending global inequality and equalizing the human condition will be impossible until the far future, when a more complete mixing of racial and ethnic groups has occurred.
Vanhanen’s work is flawed on several levels. For example, the data for the six explanatory variables are not credible. Vanhanen acknowledges problems with the reporting of tertiary education data, but he does not address issues with infant mortality rates, sanitation, and possibly even GNI, particularly in Africa.
Vanhanen’s argument that human diversity, as measured by national IQ, drives the differences in living conditions, also shows many holes. First, the book lacks a detailed explanation of how national IQ data were calculated and collected (the data were collected from a previous study, which is not described sufficiently). Also, although Vanhanen acknowledges that international IQ differences can be influenced by environmental and genetic components, he assumes that 50 percent of these differences are due to genetics. He does not explain the basis of this assumption but does reference studies that, not surprisingly, disagree with him. As IQ tests have a cultural bias, a better variable would be needed. In addition, he even lists nations—Madagascar, St. Lucia, and Cambodia—whose reported data he changed to what he thought they should be.
Furthermore, Vanhanen uses a self-created index of democratization rather than the widely employed index published by Freedom House, an independent organization. He does not cite scientific research on the role of genetics in intelligence and ignores the fact that the American Anthropological Association cautions against treating human populations as biologically distinct from each other.1
The author asserts that the prevailing worldview—that environmental, political, and socioeconomic factors are generating global inequalities in the human condition—has not been tested empirically while his theory has been so tested. However, his theory seems not to have been tested—or to have survived testing—by anyone other than the author and his immediate colleagues, unless it was tested by the Ulster Institute for Public Research. Scientists have not found significant genetic differences in intelligence between people of different races or ethnicities and definitely not between people of different nationalities. At the end of Chapter 5, Vanhanen challenges other researchers to find an alternative explanation for variations in global inequality, but no single variable is likely to explain such differences across national boundaries, if for no other reason than because in some nations the natural environment is limiting whereas in other nations the political environment is.
Vanhanen claims to explain why some nations thrive and others fail, but his theory is weak and his empirical work dubious. The social sciences could well benefit by more seriously engaging the life sciences, but not in the way presented in this book.
