Home › Forums › Inspiration / Mussar › Why are there approximately as many boys as girls?
 This topic has 34 replies, 15 voices, and was last updated 8 years, 11 months ago by Joseph.

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February 27, 2015 3:26 am at 3:26 am #614987JosephParticipant
Isn’t it amazing? If you flipped a coin ten thousand times the odds are unlikely that there would be within a small margin roughly the same number of heads as tails. Yet throughout history there have been relatively the same number of males as females born, within a small margin of difference, in every generation. You won’t find a 100 year period where the sex ratio at birth was 70% male, 30% female or 40% male, 60% female. Randomly, it should have been just as likely that the ratio would be 80%/20% as the likelihood it would be 50%/50%.
Baruch Hashem!
Lior
February 27, 2015 3:48 am at 3:48 am #1063796β DaasYochid βParticipantWhere’d you get your statistics about coins? I think with a sufficiently large sample, it would be very close to 50% each.
February 27, 2015 4:50 am at 4:50 am #1063797cozimjewishMemberwell then why is there a shidduch crisis π
February 27, 2015 5:01 am at 5:01 am #1063798Patur Aval AssurParticipantChulin 77b:
??? ??????? ?????? ???? ????? ????? ?????
Granted it’s talking about animal there.
February 27, 2015 5:03 am at 5:03 am #1063799someoneMe2MemberBecause Hashem wants it to be so…
February 27, 2015 5:08 am at 5:08 am #1063800yehudayonaParticipantNot true in China, where the one child policy led to a surplus of boys. There they have a true shidduch crisis. Hey, if all the Chinese boys converted, it would solve our shidduch crisis.
February 27, 2015 5:08 am at 5:08 am #1063801Patur Aval AssurParticipantDaasYochid:
I think Lior’s point is that granted over thousands of years it shourd be pretty equal, just like over thousands of coin flips it would probably be relatively equal, but it shouldn’t necessarily be equal in any given period of time, say every year.
February 27, 2015 5:13 am at 5:13 am #1063802β DaasYochid βParticipantIf there’s a large enough sample, it should be approximate equal in every generation.
You will find inequality in families – small sample. You will find equality in klal Yisrael and even in it’s subgroups – large sample.
February 27, 2015 6:45 am at 6:45 am #1063803nfgo3MemberIt is amazing that the opening poster is so ignorant of probability. And yehudayona is likewise ignorant. Both of you should go back to your statistics text books before you discuss statistics again.
February 27, 2015 7:22 am at 7:22 am #1063804β DaasYochid βParticipantWhy do you think yehudayona is ignorant?
February 27, 2015 7:24 am at 7:24 am #1063805JosephParticipantMany Chinese parents manipulate the results by aborting female pregnancies due to the preference for a male child and China’s onechild limit.
February 27, 2015 7:30 am at 7:30 am #1063806β DaasYochid βParticipantIs there anything in yy’s post to indicate otherwise?
February 27, 2015 7:47 am at 7:47 am #1063807JosephParticipantThe opening point that was stressed (that he replied “not true” to) is that there is a natural balance between the genders.
February 27, 2015 2:15 pm at 2:15 pm #1063808ubiquitinParticipantLior, your opening post shows a profound lack of understanding regarding statistics
“Isn’t it amazing? If you flipped a coin ten thousand times the odds are unlikely that there would be within a small margin roughly the same number of heads as tails.”
If it is an even coin the odds are extremly likely that the spread will be close (not exact) 50/50
As PAA points out over a short period you will get a wider distribution, and this is in fact the case (OF course short period is relative given an infinite number of coin flips 10,000 is a VERY short period)Though short period isnt the best term, few number of “flips” is better and this is the case. Consider a couple that has 2 children over the course of a year (or so) it obviously is not unusual if both are boys or girls, we see that often. But as the number of flips grows the closer to 50% you’d expect as in fact occurs. Even every year the number of “flips” isnt small in the U.S. alone it is around 4,000,000. And as expected it is near 50/50. But if you break down that statistic by State/County/City/Neighborhood/Block etc… You will find a wider spread in some areas (like the couple that had 2 children both boys) that “even out” over the long run.
February 27, 2015 3:38 pm at 3:38 pm #1063809nolongersingleMemberA more interesting question:
If Hashem told you that you will be having five (or any other number) of children in your life and I am giving you two choices – they can either be all boys or all girls, which should I make it be?
What would you choose?
February 27, 2015 9:20 pm at 9:20 pm #1063810Torah613TorahParticipantyehudayona: That is not due to biology, as a quick google search will tell you, but rather to female infanticide and abortion of females due to the one child policy.
nolongersingle: Both! Five boys and five girls.
February 27, 2015 9:20 pm at 9:20 pm #1063811Torah613TorahParticipantOP: Actually the more coins you drop, the closer the average will be to 50%
February 27, 2015 9:38 pm at 9:38 pm #1063813β DaasYochid βParticipantI don’t see where yehudayona attributed it to biology.
February 27, 2015 10:08 pm at 10:08 pm #1063814JosephParticipantTY T613. Even though you’re at least the fourth person (which is okay since you’re not expected to read every comment) to correct me (on a point that I was aware but slipped my mind – the horror), you did so without throwing in an adjective such as ignorant that a few others felt compelled to make for reasons only known to themselves.
March 1, 2015 10:59 pm at 10:59 pm #1063815cozimjewishMemberum, was the OP always joseph? Idk why but I thought it was s/o else
March 1, 2015 11:20 pm at 11:20 pm #1063816πRebYidd23ParticipantLior.
March 2, 2015 12:56 am at 12:56 am #1063817frumnotyeshivishParticipantLior is Joseph! Mods, you can’t say I didn’t call it. Twice. (Although mods didn’t let one of them through.)
March 2, 2015 1:44 am at 1:44 am #1063818cent_centParticipantJoseph
Your assumptions are incorrect. Statistically for a 50/50 event there is a huge difference in likelihood of it being 50/50 vs 80/20. The more times you “flip” the greater difference in likelihood. Given a large enough sample size the likelihood of even 52/48 can be infinitesimal kal v’chomer 80/20.
As a more visual example take 6 children. Since there are 2 possibilites per child (m/f), there are 2^6 = 64 possible combinations for all these children. (ie. MMMMMM, MMMMMF, FMMMMM, MMFFMF, etc..) So, because there is only 1 possible way for all to be male, the odds of 100% male is 1/64. Same with all female. The would make odds of 100% either way is only (1+1)/64 = 1/32.
However, to have 5 male and 1 female there are 6 different combination of that. MMMMMF, MMMMFM, MMMFMM, MMFMMM, MFMMMM, FMMMMM. That means there is a 6/64 chance that there will be 5 male and same for female. So, odds of there being 5 of either (which would be 83%) is 12/64 or 3/16 (approx 19%). This is more much more likely than 100% but not so likely.
4 males has 15 combinations MMMMFF, MMMFMF, MMFMMF, MFMMMF, FMMMMF, MMMFFM, MMFMFM, MFMMFM, FMMMFM, MMFFMM, MFMFMM, FMMFMM, MFFMMM, FMFMMM, FFMMMM. 4 females the same. That would be 30/64. So, 50/50 has 6430122 = 20/64 chance of happening.
To summarize likelihoods:
6M = 1/64
5M1F = 6/64
4M2F = 15/64
3M3F = 20/64
2M4F = 15/64
1M5F = 6/64
6F = 1/64
In other words, the closer you get to the 50% mark the more likelihood of it.
March 2, 2015 1:47 am at 1:47 am #1063819πRebYidd23Participantand so many pairs of posters just happened to be each other
March 2, 2015 2:18 am at 2:18 am #1063820JosephParticipantOne of the great benefits of being the OP is that everyone reads the OP and responds to it whereas if you post in middle of a thread most folks don’t even look at it and repeat the same point five others already made.
March 2, 2015 2:05 pm at 2:05 pm #1063821ubiquitinParticipantLior/joseph I’m not sure I would be proud to be the OP of this post. You claim “on a point that I was aware but slipped my mind – the horror” But the elementary statistics “slipped your mind” isnt a side point, it is the thrust of your OP
ubiquitin
March 12, 2015 3:46 am at 3:46 am #1063822Patur Aval AssurParticipantSo I did some experimentation to demonstrate that as the sample size increases the percentage moves closer to 50%.
I used a computer to randomly generate a number, either 1 or 2 (representing male or female).
Results by sample size (ss):
ss 10 = 70%
ss 100 = 55%
ss 1000 = 48%
ss 10000 = 50.22%
ss 100000 = 49.808%
ss 1000000 = 49.9077%
ss 10000000 = crashed the computer
In terms of distance from 50%:
ss 10 = 20
ss 100 = 5
ss 1000 = 2
ss 10000 = .22
ss 100000 = .192
ss 1000000 = .0923
ss 10000000 = crashed the computer
It is clearly getting significantly closer to 50% as the sample size gets larger. In fact even a sample size as small as 100 was pretty close to 50%.
March 12, 2015 1:53 pm at 1:53 pm #1063823β DaasYochid βParticipantWas it worth blowing two computers on that?
March 12, 2015 2:50 pm at 2:50 pm #1063824Sam2ParticipantDY: He only blew one. It’s the same math.
March 12, 2015 4:10 pm at 4:10 pm #1063825β DaasYochid βParticipantOh, then I guess it’s no big deal.
March 12, 2015 4:34 pm at 4:34 pm #1063826charliehallParticipant“Many Chinese parents manipulate the results by aborting female pregnancies”
This happens in much of India, too.
March 12, 2015 4:40 pm at 4:40 pm #1063827charliehallParticipantIn there United States there are about 105 baby boys born for every 100 baby girls. The likelihood that that difference is due to chance is extremely low.
March 12, 2015 4:47 pm at 4:47 pm #1063828β DaasYochid βParticipantIt’s Hashem’s way of allowing for a slight age gap.
March 12, 2015 7:02 pm at 7:02 pm #1063829Patur Aval AssurParticipantWas it worth blowing two computers on that?
DY: He only blew one. It’s the same math.
Oh, then I guess it’s no big deal.
The computer was back to normal after about 20 minutes. Although, Sam’s point notwithstanding, I did actually crash it twice – after it crashed from the 10000000, I tried doing 10 separate 1000000 (concurrently) and that also crashed the computer.
March 13, 2015 12:53 am at 12:53 am #1063830JosephParticipantIn there United States there are about 105 baby boys born for every 100 baby girls. The likelihood that that difference is due to chance is extremely low. [emphasis added]
Dr. Hall: Do you believe there is a significant amount of abortions in the U.S. specifically targeting female pregnancies? As a biostatistician, do you believe the U.S. birth rate would be near parity if not for unnatural factors?

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