Issues with the LifeStyles study data

[MCU]

A large number of LPSG members are probably familiar with the LifeStyles penis size study conducted in 2001 by the LifeStyles condom company. I know I see it quoted around here in most threads devoted to size.

For those of you not familiar, here's a quick rundown. According to the page I linked,

...of the 401 men, 300 were able to gain an erection for measurement...

so the sample size for the study is 300.

Here are the results:

LENGTH
http://img514.imageshack.us/img514/3712/lslength.png

GIRTH
http://img174.imageshack.us/img174/7262/lsgirth.png

Pretty simple, right?

Here's my issue: with a sample size of 300, each participant should have accounted for 1/300th of the total pool of data, or 0.333...%. In that case, how are these following intervals, taken from the charts above, possible:

LENGTH:
3.5" to 3.75" - 0.2%
4.00" to 4.25" - 0.2%
8.50" to 8.75" - 0.1%
8.75" to 9.00" - 0.1%

GIRTH:
6.50" to 6.75" - 0.1%

when those percentages would represent less than one participant? Furthermore, there are intervals that contain values of 0.3, 0.4, 0.5, 0.7, 0.8, 0.9, and 1.0%. Assuming a consistent rounding method was used, this shouldn't be possible when each data point represents 0.333...% of the sample group.

The only possibility I thought of was that the charts were supposed to represent the normal distribution for the entire male population, calculated from the results of the study. But if that's the case, how could the "bell" shape become so distorted around the reported mean for the girth (4.972")? The 4.75" to 5.00" interval has the highest percentage, as you'd expect, but then the distribution dips VERY low for the two adjacent intervals before rising again for the 4.25" to 4.50" and 5.25" to 5.50" intervals. There's no way a normal distribution could take that form. The page I linked to elaborates on this point a little, also.

I see these numbers used quite often on these forums, and I believe I've even seen them quoted in actual published research (albeit with a disclaimer stating that the study wasn't particularly scientific). But regardless of how scientific the study itself was, these results just shouldn't be possible unless individual participants were somehow split up into multiple intervals on the graph. And that doesn't make sense, right?

Does anyone have an explanation?

 

[kurios]

Don't have an explanation but completely agree.
Many major studies are seriously flawed. Even when the flaws are highlighted, many people still quote findings as universal fact.

 

[h8r4life]

I've quoted that study myself here a few times... but I learned stats just enough to get a B- in Principles of Statistics :smile: and promptly threw my text book into a dumpster.... so I'll be damned if I know any explaination for it, lol. I'm lucky I even still know what a fucking standard deviation is.

 

[blg3floor3]

I don't know, but I'd wager it's probably just some kind of technical issue when the graph was made. That'd be a question to ask when I was still in one of my three stats classes (god I'm glad those are over). The parameters used for a graph may not always make the data seem sensible.

On related notes though, I wonder how hard those guys were. Were they completely, full tilt, all out hard? Or just mostly? Because I know with me, although there are times it may look and seem fully hard to an observer, it actually may not be, and considering how big small differences in girth actually are, it would make a dramatic difference in a measurement. I only mention this because a girth of 6" or more being that rare seems so unlikely. 6" around just seems so small to me, but maybe I'm just used to it, having lived with it daily for so many years. Distorted/biased perceptions and such.

 

[bobbyarcter81]

I don't know, but I'd wager it's probably just some kind of technical issue when the graph was made. That'd be a question to ask when I was still in one of my three stats classes (god I'm glad those are over). The parameters used for a graph may not always make the data seem sensible.

On related notes though, I wonder how hard those guys were. Were they completely, full tilt, all out hard? Or just mostly? Because I know with me, although there are times it may look and seem fully hard to an observer, it actually may not be, and considering how big small differences in girth actually are, it would make a dramatic difference in a measurement. I only mention this because a girth of 6" or more being that rare seems so unlikely. 6" around just seems so small to me, but maybe I'm just used to it, having lived with it daily for so many years. Distorted/biased perceptions and such.

I really can't comment on the validity of the graphs since I have only taken one statistics class and that was over four years ago. However in regards to the rarity of a 6" girth, I think they are pretty spot on. I'm just assuming this based on the fact that even the self-reported measurement surveys have the same stats in regards to circumference. I do find it odd though that the self-reported measurement surveys always have a significantly larger average length, but the girth is the same as the other studies or in some cases is smaller.

 

[blg3floor3]

I really can't comment on the validity of the graphs since I have only taken one statistics class and that was over four years ago. However in regards to the rarity of a 6" girth, I think they are pretty spot on. I'm just assuming this based on the fact that even the self-reported measurement surveys have the same stats in regards to circumference.

What I'm mainly trying to reconcile is the frequency that 6" appears on these forums. It seems like it's 90%. Since you seem familiar with statistics, at least basically, you'll know what I mean when I wonder what the hell the statistical probability is that all these people really are that big around. I mean, what are the chances that the tiny population of males that has this girth, happen to all be on the internet and happen to all come here? Unless this forum is the textbook definition, poster-child of the concept of "self selection". The alternative is that there are thousands of liars here. I've encountered plenty of liars in my 12 years on the internet...but GODDAMN if that really is the case.

I do find it odd though that the self-reported measurement surveys always have a significantly larger average length, but the girth is the same as the other studies or in some cases is smaller.

Haha, yeah, I've wondered about that too. As a guy, over the years I only ever heard about length. I don't even need all of one hand to count the number of times girth/thickness/circumference has ever come up over the years. Yet, from my time on this site, it seems females become in the know about girth very early on, since they seem to be so sensitive to it and it seems to be by far the more preferred attribute. The fact that girth is almost never, ever mentioned among males is what actually led me here. I got curious about it only a year ago, measured, and googled. Thoughts on girth and thickness never even ocurred to me before then. It appears men are just waaaay caught up in length. Maybe it's because it's the far more visible and distinguishable attribute. Who knows.

 

[Mr. Sensitive]

Well, there's no statistical explanation for these numbers. I think the answer lies elsewhere, and here's my guess:

First, I think the study actually did take place in Mexico, or wherever the hell it was. Lifestyles then took the data and gave it to their product development people. But the promotion of the study and the publishing of the numbers was handled by the marketing department who took the data and transformed them into an absurdity. They did this to prevent their competitors from getting the real information which has trade value. And they did it in the expectation that the results would be endlessly quoted. Men everywhere now feel a little bit better about their penises. Increased self-confidence, the reasoning went, can only help condom sales.

Or maybe they lied to us not out of desire for profit, but out of love.

Regardless, no reliable data regarding penis size exists and it's most unlikely any ever will.

 

[knite_crawlur]

Its standard practice in surveys to apply survey weights based on demographics and socioeconomics like age, race, income, and education to correct for any unintentional systematic bias that may have been present in the survey as conducted on the ground. That's very likely where the discrepancies that you've noticed are coming from and probably shouldn't make you doubt the results of the survey. That said, an N of 300 is pretty small, so the confidence interval on these results is pretty wide.

 

[hung]

We know that most "human brain" research is funded by the advertising agencies to ascertain how to get into peoples heads.

Maybe some progressive advertising agency will do research with males to ascertain what the true measurements are. With the high rates of HIV/AIDS in the world it would be a great fit to help condom manufactures produce adequate size condoms.

I would supect that a global team of penis measurers could be employed to conduct research in most countries in the world and that each country would measure males in proportion with the number of males in that country as determined by the United Nations.

A survey of 50,000 males in the age range of 20 to 50 would be appropriate.

A costly endeavor, but certainly one that would produce the most accurate results.

I am ready for someone to measure me.

I would think that this survey would be conducted by lovely looking ladies for the hetros and great looking males for the homos so that the results would not be tainted.

 

[Stu Pendous]

knite crawlur is pretty close. I just finished my last statistics class (thank goodness). sample size of 300 is quite small to be generalizing for a whole population, but...you're math is wrong...1/300=0.003333...0.3333 would be 100/300

 

[_avg_]

but...you're math is wrong...1/300=0.003333...

^This.

 

[Kayden96]

I'm bothered by the fact that it's not really an accurate sample. It's a measurement of drunken frat boys in Mexico willing to show off their peckers. Hardly a representative sample.

It's like measuring everyone here and calling that the average. It would be a larger sample size, so it's more accurate, right?

 

[bobbyarcter81]

What I'm mainly trying to reconcile is the frequency that 6" appears on these forums. It seems like it's 90%. Since you seem familiar with statistics, at least basically, you'll know what I mean when I wonder what the hell the statistical probability is that all these people really are that big around. I mean, what are the chances that the tiny population of males that has this girth, happen to all be on the internet and happen to all come here? Unless this forum is the textbook definition, poster-child of the concept of "self selection". The alternative is that there are thousands of liars here. I've encountered plenty of liars in my 12 years on the internet...but GODDAMN if that really is the case.

I think a significant number of the guys claiming to be 6" are not completely telling the truth. Everybody wants to have this so called "perfect size" of 8"x6" that I bet it seems that 90% of the members seem to claim 6" girth, but I also bet you will also find the same frequency of members claiming 8" of length. Don't you find it a bit weird that all these guys who claim to have 6" of girth and think it is not that big also like to brag about how the girls they are with almost always comment on how big their girth is.

In regards to the OP, I think your problem with the statistics of the study may lie within the fact, which a couple of other posters pointed out, that your numbers are off by a couple of decimal places. With that said, this study should still not be taken completely seriously.

 

[blg3floor3]

Sample size is only part of the question, the issue is also whether the sample was properly representative of whatever population the researchers in the study were trying to generalize to. If the sample is properly representative of the target population, the sample doesn't necessarily have to be huge.

But in this case, the study fell short on that too, so long as we're speaking in strictly technical, academic terms.

It's a measurement of drunken frat boys in Mexico willing to show off their peckers.

When I first found it, I was happy to finally find a seemingly good survey that included girth as a key point. But when I read it, I came across that. I thought "A bunch of drunk frat dudes in Mexico on spring break? Are you fucking kidding me?" Were these guys even sober and focused?

I think a significant number of the guys claiming to be 6" are not completely telling the truth. Everybody wants to have this so called "perfect size" of 8"x6" that I bet it seems that 90% of the members seem to claim 6" girth, but I also bet you will also find the same frequency of members claiming 8" of length.

Yup, I've noticed that a lot before and commented on it a few times. Surveys from women seem to point to 8x6 being the perfect, ideal size and wouldn't you know, everyone here is exactly that size.

 

[Mr. Sensitive]

Actually the OP's numbers are not off by a few decimal places. 0.333% is the smallest resolution for a sample size of 300. And the notion that some type of demographical weighting has been applied is laughable in regards to penis size.

The published results are bogus, and obviously so based on the absurdity of the numbers and based on the experience of me and my partners.

 

[MCU]

knite crawlur is pretty close. I just finished my last statistics class (thank goodness). sample size of 300 is quite small to be generalizing for a whole population, but...you're math is wrong...1/300=0.003333...0.3333 would be 100/300

No, my math was right.

1/300 = 0.00333... = 0.333...%

I wrote everything in my post in terms of percentages to match the way it was shown on the charts.

I'm bothered by the fact that it's not really an accurate sample. It's a measurement of drunken frat boys in Mexico willing to show off their peckers. Hardly a representative sample.

It's like measuring everyone here and calling that the average. It would be a larger sample size, so it's more accurate, right?

This is true also. I didn't bother to attack the study's methodology because the results shown in the charts should be impossible regardless of how the participants were chosen.

Its standard practice in surveys to apply survey weights based on demographics and socioeconomics like age, race, income, and education to correct for any unintentional systematic bias that may have been present in the survey as conducted on the ground. That's very likely where the discrepancies that you've noticed are coming from and probably shouldn't make you doubt the results of the survey. That said, an N of 300 is pretty small, so the confidence interval on these results is pretty wide.

That may be, but wouldn't the researchers require some sort of knowledge of the distribution of penis sizes in the general population in order to correct any systemic biases in their study? And if they had that knowledge, why would they need to conduct the survey in the first place? I don't mean to come off as a smart-ass in saying that; I just don't understand how that could work.

Actually the OP's numbers are not off by a few decimal places. 0.333% is the smallest resolution for a sample size of 300. And the notion that some type of demographical weighting has been applied is laughable in regards to penis size.

The published results are bogus, and obviously so based on the absurdity of the numbers and based on the experience of me and my partners.

Thank you!

 

[sendera1]

You guys raise some interesting points. I never really considered my self big or endowed. I've been with a number of women and they all mentioned that I was big. I assumed that was something women due to boost a guys ego. It's my girth that is big. I'm around 6.25" around. Since all I ever heard was that I was big I doubted them. Since the internect came out and I started googling width (I'm about 2.125" wide) and girth and discovered that I'm pretty big. I asked some of my exes about size and they confirmed that is the width that was big.

I also agree that most women like the thick ones, but it's the length that gets talked about the most. The other thing that is interesting is that even though I may big, I've never had any women go nuts about the size. They've joked about it a lot, but none have ever been size queens or anything like that.

I am not conceited or anything, but since I've always been this size I've never considered it too be big. I'm fascinated by the fact that the average is in the 4.5" to 5" area. I'm trying to imagine that size on me.

 

[Incocknito]

Maybe the data wo' extrapolated?

 

[MCU]

Maybe the data wo' extrapolated?

Could be, but if so, I'd like to know how they did it. I'd also like to know how the hell their girth graph ended up so non-bell-shaped.

 

[Mr. Sensitive]

Extrapolation implies some sort of conjecture about what data a bigger sample might produce. No sign of that here.

"Message" might be a better term for what they did to the data.