Are Corleone’s Mafiosi more likely to marry close relations? Part 3

Do members of the Mafia share more common ancestors with their brides than their non-mafiosi neighbors in Corleone? To answer this question, I created a study of Mafia marriages with a control group of randomly selected marriages performed in Corleone. I hypothesized that the control group would have a rate of consanguineous marriage close to that found throughout Sicily by Cavalli-Sforza et al (2004), and that the study group would have a higher rate than the control.

See Part 1 of this series here, and Part 2 here.

Control Group Selection

For each marriage in the study group, a marriage was randomly selected from those performed by the Catholic Church in Corleone in the same year. On average, there were 115 marriages per year. To generate one or more random record numbers for the control group, the range of record numbers used in the year a Mafia couple married was entered into an online random series generator, random.org, and the number of records needed for the control group from that year (either one or two) were returned. None of the random numbers generated matched the marriage record number of a Mafia couple already being studied.

The grooms from the control set of marriages appear in the table below:

Control grooms with profile IDs

Groom	Wikitree ID	Year of Marriage
Sebastiano Ciravolo	Ciravolo-38	1815
Salvatore Fratello	Fratello-66	1834
Mariano Cutrone	Cutrone-76	1843
Biagio Saporito	Saporito-34	1852
Luciano Provenzano	Provenzano-178	1859
Giovanni Catania	Catania-80	1862
Biagio Provenzano	Provenzano-191	1870
Antonio Ala	Ala-4	1872
Giovanni Costantino	Costantino-41	1873
Carmelo d’Anna	D’Anna-50	1880
Matteo Mangiameli	Mangiameli-67	1880
Domenico Zangara	Zangara-39	1881
Francesco di Puma	Di_Puma-1	1883
Antonino Grizzaffi	Grizzaffi-182	1884
Antonio Sartella	Sartella-1	1884
Giuseppe Cimino	Cimino-84	1887
Pietro d’Anna	D’Anna-74	1889
Giuseppe Trombaturi	Trombaturi-11	1889
Giuseppe la Cava	La_Cava-2	1893
Salvatore Pomilla	Pomilla-60	1893
Leoluca Morello	Morello-72	1894
Giuseppe Carlino	Carlino-37	1895
Bernardo Cutrone	Cutrone-79	1897
Nicolo’ di Gregorio	Di_Gregorio-26	1897
Mariano Provenzano	Provenzano-192	1898
Calogero Pecoraro	Pecoraro-32	1900
Silvestre Vajana	Vajana-1	1902
Giuseppe Verro	Verro-46	1902
Onofrio Azzara	Azzara-3	1903
Gaetano Mangano	Mangano-57	1904
Giuseppe Labruzzo	Labruzzo-39	1906
Rocco Rao	Rao-299	1906
Giuseppe di Vita	Di_Vita-2	1908
Andrea Coniglio	Coniglio-67	1909

Although some of these men and their brides married multiple times, for the purposes of this study, only one of their marriages is being compared to the study group.

Of note, Leoluca Morello (Morello-72) is a third cousin of gang leader Giuseppe Morello (Morello-35), whose two marriages are both included in the study group. Giuseppe Verro (Verro-46) is a third cousin of the trade unionist, Bernardino Verro (Verro-22), who did not marry before his assassination in 1915, and so is not a part of this study.

Family Trees

The next challenge was to create family trees for the bride and groom in each marriage being studied, in both the study and control groups. Typically a family’s genealogy is only traced 3-4 generations to determine the coefficient of relationship, a convention initially established for reasons of convenience. (Vogel and Motulsky 2010) Dispensations for marriage between closely related individuals were only required out to the degree of second cousins, who share great-grandparents, three generations back. Cavalli-Sforza et al (2004) note that the Church’s documentation, used to determine degree of consanguinity, would typically only chart family trees going back three generations. However, their published results combine all consanguineous marriages out to the degree of third cousins, who share a common ancestor four generations back, among their twice-great grandparents (great-great grandparents, or 2GG).

For each marriage in this study, family trees were built for the bride and the groom, to the fourth generation, in order to match the results of Cavalli-Sforza. Using vital records, primarily marriage records kept by the Catholic Church, individual profiles for brides, grooms, and their ancestors, have been maintained on Wikitree.com, an open source genealogy website. The Wikitree Relationship Finder was used to find common lines of descent.

Limitations

Not all family trees could be completed. The supporting documentation that Cavalli-Sforza et al used for their study are unindexed, making them unsuitable for this research project. Instead, matrimonial records for Corleone, which are indexed (and which were presumably consulted in constructing the supporting documentation), were the primary resource. Other records consulted include a Church census, baptismal and death records, immigration records, contemporary newspapers of record, and the Italian Senate and trial records mentioned in Part 2.

In some cases, the bride, groom, or one of their direct ancestors is officially illegitimate, or has moved to Corleone from another town. In other cases, the parents of the bride, groom, or one of their direct ancestors, cannot be identified, because their vital records have not been found in a diligent search.

	Parents % known	Grandparents % known	G-Grandparents % known	2GG % known
Mafia couples	1.000	0.868	0.790	0.680
Control couples	0.971	0.827	0.733	0.594
Difference	0.029	0.040	0.057	0.086
Average	0.985	0.847	0.762	0.637

In theory, 100% completion of this study, as designed, would mean finding 1,050 marriage records: fifteen ancestral marriages for of each of the seventy marriages in the study. In reality, that number is somewhat lower than 1,050, because some of the individuals in the study share common ancestors.

Overall, 98.5% of parents, and close to two-thirds of great-great grandparents are known.The rate of completion is slightly higher for the family trees of Mafia couples compared with the control group. The most common reason for an ancestor being unknown was because they were born outside of Corleone. The other two reasons were formal illegitimacy and other genealogical “brick walls.”

Next week, I will share the results.

Sources:

1. Luigi Luca Cavalli-Sforza, Antonio Moroni, and Gianna Zei. Consanguinity, Inbreeding, and Genetic Drift in Italy. Princeton University Press, 2004.
2. Michael Speicher et al, Eds. Vogel and Motulsky’s Human Genetics: Problems and Approaches. 4th Ed. Springer, 2010.

Image credit: Il Pozzoserrato, Pleasure garden with a maze