anyone good w/ MATH? what fractions of ethnicity can you be?

Question

This is a serious question and I hope I can make myself clear.
When people state their ethnicity, I understand if they say "I'm 1/2 " this or I'm "1/4" this.

a)when does this get to be silly (meaning statistically or scientifically irrelevant) in your opinion, at 1/8th? 1/16 ?

b) Must it be an even number? What combinations are possible? Can someone say they are 1/3 or 1/5 or whatever or is this sort of meaningless because you have to go back too many generations?


Sorry if this doesn't make sense. I'm very smart but math sort of makes me freak out. thanks!

Answer 1

I don't think ethnicity would ever be irrelevent. The denominator of the fraction definitely must be even - 2^n. I can't come up with some that would reduce to 1/3 or 1/5 right now. I'll continue towwork on it.

Answer 2

Part (b) is easy. Each child has two parents. Each of the parents had two parents. No matter how far back you go, the denominator of your fraction must always be a power of two (2, 4, 8, 16, 32, ...). The numerator will be the number of ancestors were of a certain ethnicity.

For example, going back three generations, suppose three of a person's great-grandparents were English, one was Scottish, and four were Dutch. The person's ethnicity is 3 / 8 English, 1 / 8 Scottish, and [4 / 8 =] 1 / 2 Dutch.

As for part (a) to your question, the best answer I can give is that relevance or irrelevance can only be measured by the listener. In a culture (such as those of Native Americans or Asians or Pacific Islanders) where there's a strong oral tradition, the listener might want to hear as much detail as possible. In Western civilizations where there's more of a desire to get down to business right away, the listener might not give a whit or start glassing over details more than just parents or grandparents. Statistically, anything less than 2½% (in the case of ancestry, less than 1 / 32) is usually considered more than enough.

Answer 3

I have the same kind of question. It seems that ethnicity would be additive.

Let me try just off the cuff to turn it into a formula:

target ethnicity coefficient = 1 over ( 2 ^ number of generations removed from pureblood ).

Total ethnicity = sum of all target ethnicity coefficients.

Thus, if your mom is Martian, you're half Martian. If your Dad's mom is Martian, you're 1/4 Martian, and if your Dad's dad's mom is Martian, you're 1/8 Martian, and if mom, grandma and great-grandma (in this instance) are ALL Martian, then you're 7/8 Martian. If it's just mom and great-grandma, you're 5/8 Martian; if it's just grandma and great-grandma, you're 3/8 Martian, and if it's Mom and grandma, you're 3/4 Martian.

There are all sorts of ways to add up powers of two this way, but whenever you do, the LCD (Lowest Common Denominator) is going to be a power of two.

If someone says they're (some number n) divided by (some number m) ethnic, if m is not a power of 2, they've rounded or don't know how to add fractions. 1/5 German is not possible, and neither is 1/3 French, BUT you can get close to 1/5 with 51/256 (1/8 + 1/16 + 1/128 + 1/256) or close to 1/3 with 43/128 (1/4 + 1/16 + 1/64 + 1/128)

This is the most long-winded answer I've ever given on Y!A, but at least I had fun. :-) I hope you could follow my tortured logic.

Answer 4

First: It always has to be even because there are only two (2) sexes. In fact it HAS to be a power of "2" (2^n; where n is a positive integer; 2,4,8,16,32,64,128,256,etc.)
Second: I don't think it matters in any proportion, but I think it'll even become medically irrelevant beyond 1/4 except for very strange hereditary diseases.

Answer 5

I'm 1/128 th native american, however I can see certain physical features that are more of that descent than my other nationalities. So, I guess it depends more on biology than mathematical precision.

Answer 6

there not math problems ... it's a way to identify ones self....
if they make it complicated for you, just know that they are complicated (complex) people and some like to be that way...
just ask for the cake, not the recipe

Answer 7

It's all pointless since no person can prove a bloodline back to it's origination. So it's all pointless!!!