Introduction and Issue

[khaz]

Hey guys, first post, interesting site.

I don't want to put anyone off side here, but I have been reading over this site for the last couple of weeks and I believe there is rampant misinformation on the site, specifically regarding penis size.

To illustrate:
Let's take a reputable study on penis size, for example, the Lifestyle condom study conducted in 2001 by Ansell. They found that the average penis size is 5.9 inches, with an SD of 0.8 inches.

This is one of the higher estimates of average size and SD.

Given these parameters we can compute a z-score, which allows us to determine the probabilities of the sizes of certain penises. Crucially we must also assume that penis size is NORMALLY DISTRIBUTED. All of the large studies have found penis sizes to be normally distributed.

So we can now work out the probability of a 10 inch penis:
p= 0.00000149 (actually a slight overestimation)
or
assuming 6 billion people there should be 8.94 people IN THE ENTIRE WORLD that have a 10 inch or bigger penis.

Contrast that with the claims of penis size found on this site.

I remember reading a thread with a size queen looking for a 13.5 inch penis, for which the probability is so low that even the statistical package (sic) that I am using just tells me that there is not enough room for the digits.

For interest (if I havn't bored anyone fully yet) here are some probabilities of being bigger than some other sizes.

9 = .0000533 or around 3198 people in the world
8 = .0043325 or around 259,950 people
7 = .135661 or around 8,139,660 people

Again, statistics is a funny field and there very well could be people that defy the odds, but keep in mind that the figures above are calculated off a mean and SD which is higher than one normally found, so the numbers are likely to be EVEN SMALLER.

Hope I havn't annoyed anyone too much, feel free to rip my superficial analysis to threads with a comment, and in case you are wondering:
7.25 x 5.25

(to a certain unnamed size queen I scrape into the average category)

 

[Big Del]

Welcome

Of the 6 Billion people in the world approx 50% are also women!

I thought I saw some stats that said average cock size was circa 5.5 inches

But there are plenty of big cocks to be seen on here and elsewhere so I think some of your maths may be a bit off

Cheers

 

[khaz]

Hahah, right amateurs mistake, that's my misogyny showing through.

All the numbers above should be HALVED.

 

[davidjh7]

Statistics, as you say, is a funny field, and humans are notorious for screwing up mathematical models. The main problem with applying statistical analysis to the siezes, and distribution of penis sizes, is the basic problem that the sample sizes are not large enough to acheive a high confidence level in the statistical analysis---in other words, the mathematical model itself is flawed due to lack of data. I don't know if there will ever be a really definitive study of the distribution of penis sizes in the world. I have spent a good part of my adult life, as part of the hobby of studying human sexuality, and the best I have even been able to come up with is that approximately 85% of the male population of the world is between 5-7", with a ROUGH standard deviation of about an inch. The mean still floats somewhere around 6", but the peak of the curve is pretty broad, but the slopes fall off rapidly after the range I mentioned, both smaller and larger. There has been enough verification to show that just on this site, the number of 10" and above exceeds your statistical numbers Always has to be some joker to screw up the math.

Hey guys, first post, interesting site.

I don't want to put anyone off side here, but I have been reading over this site for the last couple of weeks and I believe there is rampant misinformation on the site, specifically regarding penis size.

To illustrate:
Let's take a reputable study on penis size, for example, the Lifestyle condom study conducted in 2001 by Ansell. They found that the average penis size is 5.9 inches, with an SD of 0.8 inches.

This is one of the higher estimates of average size and SD.

Given these parameters we can compute a z-score, which allows us to determine the probabilities of the sizes of certain penises. Crucially we must also assume that penis size is NORMALLY DISTRIBUTED. All of the large studies have found penis sizes to be normally distributed.

So we can now work out the probability of a 10 inch penis:
p= 0.00000149 (actually a slight overestimation)
or
assuming 6 billion people there should be 8.94 people IN THE ENTIRE WORLD that have a 10 inch or bigger penis.

Contrast that with the claims of penis size found on this site.

I remember reading a thread with a size queen looking for a 13.5 inch penis, for which the probability is so low that even the statistical package (sic) that I am using just tells me that there is not enough room for the digits.

For interest (if I havn't bored anyone fully yet) here are some probabilities of being bigger than some other sizes.

9 = .0000533 or around 3198 people in the world
8 = .0043325 or around 259,950 people
7 = .135661 or around 8,139,660 people

Again, statistics is a funny field and there very well could be people that defy the odds, but keep in mind that the figures above are calculated off a mean and SD which is higher than one normally found, so the numbers are likely to be EVEN SMALLER.

Hope I havn't annoyed anyone too much, feel free to rip my superficial analysis to threads with a comment, and in case you are wondering:
7.25 x 5.25

(to a certain unnamed size queen I scrape into the average category)

 

[khaz]

The lifestyle study was based on a sample size of 300. Not huge, but enough to determine mean and SD accurately. In addition, the BJU review of many penis length studies found similar results for both mean and SD.

I think the major issue may be violations of multivariate normaility. Some studies have found penis size to be non-normally distributed, famously the Kinsey study. Though I think this may have been because they allowed self report (which in my opinion means you can disregard the results).

But I can't ignore that on this site there are undeniably pictures showing 10inch+ penises. As a keen statistician I find it hard to reconcile what I KNOW about probability and what I see here.

 

[davidjh7]

Humans will always foul up a nice clean statistic . The sample size may have been STATISTICALLY large enough to meet a perceived model, but I still contend that until you can get a much larger sample size to get a more reliable model, the inconsitancy is going to go unresolved. I had a theory on why the Kinsey study has a fairly large inconsistancy with other studies. Kinsey didn;t ask the participants to measure and report a number. He mailed out cards with the questionaire and asked them to make a mark on the card. Now, consider something---if you are going to try and mark the end of your dick on a card, is it easier to lay your dick on top of the card and mark it, or put the card on top of your dick and mark it? I contend that most of the participants put the card un the bottom and marked it, and as has been clearly established, measuring from the bottom side will give you a significantly larger reading than measuring from the top side. I believe it was Master's and Johnson in the 70's who established the "uniform" method to provide the most consistant results, ergo, measuring along the top, pressed into the pubic bone to give a "hard" reference point. I don't have evidence other than logic and human nature to support my hpothesis, but until I have evidence otherwise, I'll go on thinking this is the most likely explanation for the discrepancy. Opinions will of course vary. :biggrin1:

The lifestyle study was based on a sample size of 300. Not huge, but enough to determine mean and SD accurately. In addition, the BJU review of many penis length studies found similar results for both mean and SD.

I think the major issue may be violations of multivariate normaility. Some studies have found penis size to be non-normally distributed, famously the Kinsey study. Though I think this may have been because they allowed self report (which in my opinion means you can disregard the results).

But I can't ignore that on this site there are undeniably pictures showing 10inch+ penises. As a keen statistician I find it hard to reconcile what I KNOW about probability and what I see here.