Coon's Bizarre Conclusion Explained

In the chapter on Italy in his book The Races of Europe, anthropologist Carleton S. Coon describes Northern and Southern Italians as being very similar in both subracial make-up and pigmentation (which I've confirmed with facial composites):

In the population of [northern Italy] there is a strong prevalence of Alpine and Dinaric types, especially the former, but approximately one-third of the population is long-headed or nearly so. [...] In other words, the southern Italians are a blend for the most part of Alpines and small Mediterraneans, while among the northern Italians the most important dolichocephalic strain is the Atlanto-Mediterranean. [...] The pigmentation [in northern Italy] is lighter than in southern Italy, but still prevailingly brunet.

Alpine

Small Mediterranean

Dinaric

Atlanto-Mediterranean

But then in the last paragraph, he concludes with this bizarre statement that seems to contradict (or at least greatly exaggerate) everything that came before:

No country in Europe in which one language and one cultural tradition prevail shows a greater diversity of race between its southern and its northern extremities than does Italy.

To unravel this mystery, we need to understand that Coon's book started out as a revision of an earlier work by William Z. Ripley, also called The Races of Europe. I was looking through it recently and found this nearly identical statement, with an added twist at the end:

We have now seen how gradual is the transition from one half of Italy to the other [with] profound contrasts between the extremes of north and south. These must ever stand as witness to differences of physical origin as wide apart as Asia is from Africa.

It seems pretty clear that Coon's statement is a holdover from Ripley. So are Northern and Southern Italians really as different from each other as Asians are from Africans? Not exactly. Ripley's book dates back to the 19th century, and his analysis, which fell into what Coon called the "prestatistical school", was accordingly very rudimentary. He based his conclusions almost entirely on the single craniofacial trait of cephalic index. This led him to believe that brachycephalic (round-headed) Alpines and Dinarics were similar to Mongoloids, and dolichocephalic (long-headed) Mediterraneans and Nordics were similar to Negroids, an absurd notion that must have seemed reasonable given the limited knowledge of the time. Here's the passage where he explains his peculiar classification system and how Italians fit into it:

The most conspicuous feature of our map of cephalic index for western Europe is that here within a limited area all the extremes of head form known to the human race are crowded together. In other words, the so-called white race of Europe is not physically a uniform and intermediate type in the proportions of the head between the brachycephalic Asiatics and the long-headed negroes of Africa. A few years ago it was believed that this was true. More recently, detailed research has revealed hitherto unsuspected limits of variation. They are roughly indicated by our portraits of living European types at page 39. In the high Alps of northwestern Italy are communes with an average index of 89, an extreme of round-headedness not equalled anywhere else in the world save in the Balkan Peninsula and in Asia Minor. This type of head prevails all through the Alps, quite irrespective of political frontiers. These superficial boundaries are indicated in white lines upon the map to show their independence of racial limits. There is no essential difference in head form between the Bavarians and Italian Piedmontese, or between the French Savoyards and the Tyrolese.

From what has been said, it will appear that these Alpine populations in purity exceed any known tribes of central Asia in the breadth of their heads. Yet within three hundred miles as the crow flies, in the island of Corsica, are communes with an average cephalic index of 73. These mountaineers of inland Corsica are thus as long-headed as any tribe of Australians, the wood Veddahs of Ceylon [Sri Lanka], or any African negroes of which we have extended observations. A little way farther to the north there are other populations in Scotland, Ireland, and Scandinavia which are almost as widely different from the Alpine peoples in the proportions of the head as are the Corsicans. An example of extreme individual variation downward is shown in our Teutonic type at page 39, which has a lower index than any recorded for the longest-headed primitive races known. Nor is this all. Pass to northern Scandinavia, and we find among the Lapps, again, one of the broadest-headed peoples of the earth, of a type shown in our series of portraits.

So remarkably sudden are these transitions that one is tempted at first to regard them as the results of chance. Further examination is needed to show that it must be due to law. Proof of this is offered by the map itself; for it indicates a uniform gradation of head form from several specific centres of distribution outward. Consider Italy, for example, where over three hundred thousand individuals, from every little hamlet, have been measured in detail. The transition from north to south is, as we shall see, perfectly consistent. The people of the extreme south are like the Africans among our portraits at page 45 in respect to the head form; gradually the type changes until in Piedmont we reach an extreme perfectly similar to that depicted on our other page of brachycephalic Asiatic types. So it is all over the continent. Each detailed research is a check on its neighbor. There is no escape from the conclusion that we have to do with law.

Two distinct varieties of man, measured by the head form alone, are to be found within the confines of this little continent. One occupies the heart of western Europe as an outpost of the great racial type which covers all Asia and most of eastern Europe as well. The other, to which we as Anglo-Saxons owe allegiance, seems to hang upon the outskirts of Europe, intrenched in purity in the islands and peninsulas alone. Northern Africa, as we have already observed, is to be classed with these. Furthermore, this long-headed type appears to be aggregated about two distinct centers of distribution — in the north and south respectively. In the next chapter we shall show that these two centres of long-headedness are again divided from one another in respect of both colour of hair and eyes and stature. From the final combination of all these bodily characteristics we discover that in reality in Europe we have to do with three physical types, and not two. Thus we reject at once that old classification in our geographies of all the people of Europe under a single title of the white, the Indo-Germanic, Caucasian, or Aryan race. Europe, instead of being a monotonous entity, is a most variegated patchwork of physical types. Each has a history of its own, to be worked out from a study of the living men. Upon the combination of these racial types in varying proportions one with another the superstructure of nationality has been raised.

Sure enough, when we look at his map of cephalic index in Europe, the extreme North and extreme South of Italy are farther apart in average cephalic index than any other nation in Europe. But of course, we know that this isn't a racial difference, and that when multiple craniofacial traits are analyzed, all Caucasoids cluster together, away from Asians and Africans. Coon knew this as well, which is why he ignored Ripley's rejection of a unified white race, and was able to identify Dinarics as "Mediterranean derivatives" despite their different head shape. So the only reasonable explanation for his retaining Ripley's erroneous conclusion about Italians is that it was an oversight.