Male / Female Rule

Many years ago I made up a rule based on some casual observations. That if someone's name were to end in a vowel, they would tend to be a female. I had guessed this to be correct approximately 80% of the time.

Recently, I happened upon a large table of names, and their frequency in the population this morning and wanted to more empirically test my hypothesis. Here's what I came up with.

I began be isolating the last letter of each name in Excel and testing to see if it was A, E, I, O, U, or Y. Y is sometimes a vowel, but I lack a good rule to test for this in Excel, so I assumed they were all vowels. This seemed fair since the assumption was made on both male and female datasets. I totaled the frequency occurrence in population column for entries that met the conditions of my vowel test.

The male and female datasets totaled to account for 90.05% and 89.94% of their population, respectively. The remainder was assumed to be uniform to the portion I had (assumption of homogeneity), so each dataset was equalized to 100%.

An analysis of males showed that 24.42% name ended with a vowel, which was equalized up to 27.12%. Females with vowels at the end of their name's were 74.29% raw, and 86.60% equalized.

More conversions were still required though. Females make up 51.92% of the USA population, so another round of equalization was required. Folding that out into a population estimate for the USA looks like this.

Vowel ending Consonant ending
Female 44.96% 6.96%
Male 13.04% 35.04%

If you pull out only those whose names end in a vowel and test the frequency of male vs female, you'll see that 77.52% of the time the name will be that of a female, and 22.48% of the time it will be male.

“Most Common Male Names in the U.S.” Mongabay, 1 Jan. 2016, names.mongabay.com/male_names_alpha.htm.
“Most Common Female Names in the U.S.” Mongabay, 1 Jan. 2016, names.mongabay.com/female_names_alpha.htm.


Tennessee Mississippian Strata - Fossils - Hartselle sandstone & Monteagle limestone

collection_no identified_name identified_rank accepted_name accepted_rank early_interval max_ma min_ma
2710 Acrocrinus sp. genus Acrocrinus genus Brigantian 336 326.4
Allocatillocrinus sp. genus Allocatillocrinus genus Brigantian 336 326.4
Aphelecrinus sp. genus Aphelecrinus genus Brigantian 336 326.4
Armenocrinus sp. genus Armenocrinus genus Brigantian 336 326.4
Batocrinus sp. genus Batocrinus genus Brigantian 336 326.4
Camptocrinus sp. genus Camptocrinus genus Brigantian 336 326.4
Cymbiocrinus sp. genus Cymbiocrinus genus Brigantian 336 326.4
Decadocrinus sp. genus Decadocrinus genus Brigantian 336 326.4
Dichocrinus sp. genus Dichocrinus genus Brigantian 336 326.4
Dinotocrinus sp. genus Dinotocrinus genus Brigantian 336 326.4
Linocrinus sp. genus Linocrinus genus Brigantian 336 326.4
Phanocrinus sp. genus Phanocrinus genus Brigantian 336 326.4
Platycrinites sp. genus Platycrinites genus Brigantian 336 326.4
Rhopocrinus sp. genus Rhopocrinus genus Brigantian 336 326.4
Diploblastus sp. genus Diploblastus genus Brigantian 336 326.4
Pentremites sp. genus Pentremites genus Brigantian 336 326.4
Discocystis sp. genus Discocystis genus Brigantian 336 326.4
Onychaster sp. genus Onychaster genus Brigantian 336 326.4
Anthracospirifer sp. genus Anthracospirifer genus Brigantian 336 326.4
Beecheria sp. genus Beecheria genus Brigantian 336 326.4
Cleiothyridina sp. genus Cleiothyridina genus Brigantian 336 326.4
Composita sp. genus Composita genus Brigantian 336 326.4
Echinoconchus sp. genus Echinoconchus genus Brigantian 336 326.4
Eumetria sp. genus Eumetria genus Brigantian 336 326.4
Girtyella sp. genus Girtyella genus Brigantian 336 326.4
Inflatia sp. genus Inflatia genus Brigantian 336 326.4
Productus indet. genus Productus genus Brigantian 336 326.4
Punctospirifer sp. genus Punctospirifer genus Brigantian 336 326.4
Reticulariina sp. genus Reticulariina genus Brigantian 336 326.4
Schellwienella sp. genus Schellwienella genus Brigantian 336 326.4
Torynifer sp. genus Torynifer genus Brigantian 336 326.4
Bryozoa indet. phylum Bryozoa phylum Brigantian 336 326.4
Porifera indet. phylum Porifera phylum Brigantian 336 326.4
Anthozoa indet. class Anthozoa class Brigantian 336 326.4
Gastropoda indet. class Gastropoda class Brigantian 336 326.4
Trilobita indet. class Trilobita class Brigantian 336 326.4
28 Wewokella costata species Wewokella genus Brigantian 336 326.4
Data Provider The Paleobiology Database
Data Source The Paleobiology Database
Data License Creative Commons CC-BY
License URL http://creativecommons.org/licenses/by/4.0/
Documentation URL http://paleobiodb.org/data1.2/occs/list_doc.html
Data URL http://paleobiodb.org/data1.2/occs/list.csv?datainfo&rowcount&strat=monteagle%20limestone
Data URL http://paleobiodb.org/data1.2/occs/list.csv?datainfo&rowcount&strat=hartselle%20sandstone


Tennessee Mississippian Strata - Fossils - Bangor limestone

Distribution of Bangor Limestone
Distribution of Bangor Limestone

Fossils described in the Bangor limestone
collection_no accepted_name early_interval / age
76726 Caninia Chesterian 339.4-318.1 ma
Echinodermata Chesterian 339.4-318.1 ma
Bryozoa Chesterian 339.4-318.1 ma
Gastropoda Chesterian 339.4-318.1 ma
Bivalvia Chesterian 339.4-318.1 ma
Archimedes Chesterian 339.4-318.1 ma
Ostracoda Chesterian 339.4-318.1 ma
Foraminifera Chesterian 339.4-318.1 ma
84104 Psammodus Late Mississippian 326.4-318.1 ma

Photographs of Bangor limestone fossils

Archimedes, Bangor limestone, east Tennessee
Eridopora, Bangor limestone, East TennesseeBlastoids, Bangor limestone, East TennesseeUnknown

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