If you have 5 girls the odds that the next one is a girl, baring any genetic issues, is still 50/50. But the odds of having 6 girls in a row is NOT 50/50. Why are the odds still 50/50 when it would be unlikely to have 6 girls in a row? Why don’t the odds that it’s a girl go down and odds it’s a boy go up? Isn’t it more likely you’ll have a boy with each passing girl but yet it’s still 50/50?
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couple of things. first it’s not 50/50 in terms of humanity in total, slightly more boys are born. Secondly, it’s not 50/50 in any given male either. Some men are pre-disposed to have girls or boys.
Its like saying why is it less likely to flip heads multiple times prior to flipping. The odds are roughly.5*.5 for twice (.25), if the odds are different it means that the initial odds are not .5
>Why are the odds still 50/50 when it would be unlikely to have 6 girls in a row?
Because each event is independent of the previous. What you’re thinking of is known as a the gambler’s fallacy, where someone believes that a heads is more likely after a long string of tails. The odds are actually unchanged because each flip of a coin is independent of the previous flip.
Because it’s independent of the previous outcome. The body doesn’t care what the previous result was
Because that next child is a singular event.
If you flip a coin 5 times and get heads each time, the next flip is still 50/50.
Because independent event probabilies aren’t influenced by prior outcomes. If you flip a coin and get heads, you aren’t suddenly more likely to get tails the next time you flip it.
The likelihood of the 6th boy or girl is always 50/50 because there are only two outcomes.
It is different if you are talking about having 6 girls consecutively. Having 6 girls consecutively is 0.5 raised to the power of 6, which is 0.015625, so you have about 1.6% chance of having 6 girls consecutively.
roll a dice 10 times. did your chances of rolling a six in your tenth roll decrease depending on what you had in the previous 9 rolls?
do you ever hear people going around saying “i rolled too many dice in my life, now my odds are pretty straightforward” ?
Basic rules of probability. Your assumption is wrong because it’s based on the gamblers fallacy.
Look up Gambler’s fallacy.
There are factors other than the odds that affect the sex of a baby. But across the world the odds work out close to 50:50.
Yes, looking back retroactively, you can see it was unlikely to get six girls in a row.
But here’s the thing – the odds of that don’t matter anymore because we already know it happened. It’s in the past. Locked in, 100% that it happened.
The odds you’re talking are about guessing the future. And there’s only one event coming up in the future – what’s the seventh kid going to be? 50/50 that it’s a boy or a girl. (Actually 51% boy/49% girl in human biology, but ignore that for now).
So you have to be careful about what odds you’re talking about when guessing the future. The odds of all six babies being born in the future as girls is 1.5625%. But that’s only if you force me to lock in all the bets before the first child is born. If I get to make a new bet for each child on its own, I’d always have 50% odds.
My dad has all girls (5) so there gotta be some kind of genetic predisposition or hormone factor? My dad is definitely on the sensitive side, not stereotypical testosterone-filled, sporty guy.
What you’re talking about is called the gambler’s fallacy. It’s a well known phenomenon where when people see a “lucky” streak, they intuitively believe that some other value is “due” because long streaks should be rare. Let’s simplify the issue and say we are looking at 8 families, all with 2 children and expecting their 3rd child. We are also using individual families here to represent the statistical average of a large number of families. So, on average, our 8 exemplars here, have 2 families with 2 girls, 2 families with 2 boys, and 4 families with 1 each (with half having the male first, and half having the female first. So if we just look at those two families with the two girls, on average one will have a boy and one will have a girl (50% chance). But after all 8 families had their 3rd baby, only 1 of the 8 would have 3 girls (12.5%). That’s where the disconnect comes in. The odd of having 3 (or 6) girls in a row is low but if you ignore all the other people with a 0% chance to have 6 girls in row because they’ve already had a boy, and just look at the single odds of that one birth with the knowledge of all the prior births, it’s still 50/50.
It depends
It’s a fifty fifty chance because you’re either going to have a boy or a girl, you’re not gonna have a guppy. If you could have a guppy, it would be a 1 in 3 chance?
The odds only mean that there’s a 50/50 chance to have a boy or a girl. Doesn’t matter how many girls or boys you had first. It’ll always be 50/50 since you can only have a male or female.
Your odds of having a girl is 50/50 regardless of what you’ve had before because they are independent of each other. Having a girl previously doesn’t change your odds of having a girl the next time.
Your rate of having 6 girls in a row is a lot less (.50 x .50 x .50 x .50 x .50 x .50 = 1.56%) because they are dependent of each other. To have 6 girls in a row, it’s dependent on each birth being a girl. If you have a boy anywhere in that chain of events, your odds of having 6 girls in a row drops to 0%. However, your chance of having the next one be a girl is still 50%.
Watch a video on “the Monty hall problem”.
It explains how statistics work in cases like this.
The sex of the previous births is not impacting the odds of the outcome of the next one. It has been explained but in human terms, there are factors that affect outcomes that make some events statistically more probable or less probable.
Team A practices four hours a day, 3x a week for 4 weeks, Team B practiced 1 hour 1x a week for 6 weeks. What are the odds Team A wins the game against Team B? The relevant factor here, all else being the same, is amount of practice.
The coach for Team A has 5 sons already and his wife is pregnant. Does that change the odds that Team A wins? Why would it affect the outcome of a game? It also doesn’t affect the sex of the coach’s new baby.
It’s not 50/50. There are genetic dispositions.
If you do coin flips, you’ll notice that true randomness will sometimes have looong chains of all heads or all tails, even though each flip’s odds are 50/50. It just happens like that
The reason that having 6 girls in a row is very unlikely is that if you have 6 children there are a total of 64 different combinations of gender you could get (BBBBBB, BBBBBG, etc) and only one of them gives you 6 girls. The chance, therefore, is 1/64.
If however you’ve already had 5 girls, then the chance of getting any of those combinations that don’t start with GGGGG is zero. You already know that you can’t possibly end up with any of those combos, so we don’t have to consider them. The only remaining possible combos now are GGGGGB or GGGGGG, so we end up with a 1/2 chance or a 50/50 shot at 6 girls.
What changes things is not the timing but the knowledge that we can exclude those possible combinations. If you only knew that someone had 6 children and not whether they were boys or girls, it would again be a 1/64 chance that all of them were girls.
You’re conflating what already happened with what will happen. It was unlikely to get 5 girls in a row, but it already happened. The past events have no effect on what happens next, otherwise I’d be wondering what force is corralling a Y chromosome sperm into the egg after a bunch of girls are born.
Lookup the gambler’s fallacy, odds don’t change based on previous results. Also, the 50/50 split is for the population, not any given couple. The ratio of viable X to Y sperm can vary from man to man and that will impact the results for any particular family.
The odds go back to 50/50 no matter how many kids you already have…
Because each sperm is the result of splitting one xy cell into one x and one y. The existence of other kids from the same parents doesn’t change that.
The odds of having 6 girls in a row are exactly the same as the odds of having 5 girls and then a boy. At least if you assume that gender odds are actually 50/50, which is not really true.
What you are thinking of is the odds of having at least one boy being higher than having only girls. But that’s only more probable if you are not caring about the order of them being born, because there are several scenarios resulting in at least one boy while there is only one scenario leading to all girls. Still, each individual scenario still is exactly as likely as any other.
imagine having 6 girls as an event (having 1 girl) repeated 6 times.
Each time is independent from the time before, and is not influenced by the gender of previous baby.
probability of having a girl 1 time : 0.5
probability of it happening 6 times : 0.5×0.5×0.5×0.5×0.5×0.5=(0.5)^6
And the reason the chance of having a girl is 50% is bcz the number of sperm that contain the y gene (gene that is responsible of the development of the male gender) is equal to the one that contain the X gene (it will give a girl)
It’s not truly 50/50, but we don’t really have any way of affecting it that’s feasible, so we assume it’s 50/50.
next one being a girl and six girls in a row are two very different situations, the former is a single “roll” and the latter is six “rolls” sequentially
did you know it isn’t?
In peacetime about 105 boys are born for every 100 girls. During and just after wars the ratio mysteriously increases to about 108 boys for every 100 girls. For the first time in World War II, this phenomenon has appeared in several warring nations of Europe, according to reports from Sweden last fortnight.
OPEN THE DAMN schools oh my god.
The short answer is independent odds, but let’s clarify:
Probability is, in basis, [number of favourable outcomes]/[total number of possible outcomes]
Having kids (or coinflips), there are 2 possible outcome for each instance. With N instances, there are 2^N possible outcomes. E.g. two kids, there are 2^2 =4 outcomes: GG, GB, BG, BB. Notice that a different order is considered a different outcome; GB amd BG are both included. The Probability of 2 girls is 1 in 4, whereas 1girl and a boy becomes 2 in 4, as there are 2 orders to make that happen.
In general, the odds of N of the same kids (or coinflips) decreases with N: the number of possible outcomes is 2^N , but the number of outcomes of “all girls” is always only 1: For N=6; GGGGGG. However there’s 6 outcomes that include 1 boy:
From there it follows that the odds of having 1 boy anywhere in the sequence of 6, is 6 times higher then not allowing any boys at all.
However, how many total outcomes are there for having FIRST 5 girls, and then another kid? Just 2! GGGGGG or GGGGGB. That means either outcome has a 1 in 2 probability. Notice the difference with the above: there are 2^N ways outcomes for 6 kids, with 1 being “all girls” and 6 being “5 girls and a boy at some point, vs only 2 total outcomes for “5 girls first and then another kid”, with 1 for “final kid is boy” and another “final kid is girl”.
Having six girls in a row is still a random reluctant
Consider that the following are two different scenarios:
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The chances of all 6 children being women in those scenarios are, respectively.
Stressing the importance of this again: it doesn’t matter what the odds of something happening were, if you’re considering a scenario where it’s a given it happened.
It’s not always 50/50 – the podcast link below explains historical statistical outliers, and the reason why. IMHO it’s a fascinating listen – Hannah Fry.
https://podcasts.apple.com/gb/podcast/uncharted-with-hannah-fry/id1707808635?i=1000629026189
You already have a million answers but I’ll answer again in case this one clicks.
If you ask “What are the odds that my 6th child will be a girl” the answer is 50%.
If you ask “What are the odds that my 6th child will be a girl AND every time I had a child previously they always came out girl?” that is a very different question. The answer to that is 50% x 50% x 50% x 50% x 50% x 50%.
That’s why considering the 6 births as an event gives you a very different probability than just considering one at a time.
Each time a new egg is fertilized (presumably a year or so after the last one), it’s a brand new batch of sperm. The genes within the sperm determined the sex of the child. Each time this happens there are millions (hundreds of millions) of sperm. They are almost perfectly divided male/female.
So – when one of those sperm fertilizes an egg: it’s a 50/50 chance it’ll a boy or a girl. What has happened years before has absolutely no bearing on that moment. So – each time there’s a child: it’s one or the other, but it’s always 50/50.
And it’s not more likely that you’ll have either a boy or a girl. It’s always 50/50.
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Now, if you’re thinking ahead and your’e wondering what the odds are that you’ll have 2 girls or 3 girls or 6 girls… You have some math to do.
Two girls: you multiply the probably of a girl the first time, times the probability of a girl the second time. So – it’s .5*.5 which is .25. If you really suss out the math, you’ll find that if a couple had two children, the odds are than 1/2 of the time, they’ll have one boy and one girl. But, 1/4 of the time they’ll have two girls. And 1/4 of the time, they’ll have two boys.
The same math can be applied to figure out the odds of having 6 girls in a row:
0.5^6, or 0.015 or 1.5%. Now, if you’re already had 5 girls, you’ve beaten some pretty tough odds to get that far, but the next child is still 50/50.
They’re not.
>If you have 5 girls the odds that the next one is a girl, baring any genetic issues, is still 50/50. But the odds of having 6 girls in a row is NOT 50/50. Why are the odds still 50/50 when it would be unlikely to have 6 girls in a row? Why don’t the odds that it’s a girl go down and odds it’s a boy go up? Isn’t it more likely you’ll have a boy with each passing girl but yet it’s still 50/50?
It’s not 50/50 if the same two people have five girls in a row, because while that may be chance there also may be an issue that’s causing that.
You’re backwards — the longer it goes on the LESS likely you are to have a boy.
Because getting 6 girls in a row is not more unlikely than getting 5 girls and 1 boy in a sequence. The only difference is that you don’t find the latter event “interesting”.
Using a smaller example (N = 3)
These are all possible outcomes:
B B B
B B G
B G B
B G G
G B B
G B G
G G B
G G G <- your interest
If you notice, all events are 1/8, however, your brain is only interested in the last one and ignores everything else.
Your brain might actually be wondering what is the chance of getting ALL GIRLS. In that case, then yes, that is 1/8, getting at least 1 girl is 7/8, at least 2 girls is 3/8. So yes, it’s very unlikely if you ask THAT question.
TL;DR: There is absolutely no reason to think that the next event depends on the previous events for this problem statement.
Think of it this way. The odds of getting 6 girls in a row is unlikely because that’s 6 coin flips. Each one has a 50% chance.
If you already had 5 girls, it’s no longer 6 coin flips. 5 of the coin flips have already been decided – each of those 5 girls have a 100% chance of being a girl, because they already are. That means having a 6th girl given that you already have 5 is 50%.