Sexual Relationships 
Sexual Health 
Continued from part 1 of "Dick Data".
NOTE: I originally had all of the sources and links at the end of this part of the MyTake, but they somehow got deleted in the process of copying, pasting, editing, and uploading this portion of the discussion. I would try to find all of the sources and links again, but I believe there was around 35-40 of them and I have already spent several, several hours on this post and really do not want to spend several more trying to find all of those links. However, if you are interested in the sources that I used as a reference for any of the data in this two part series, please leave a comment describing what information you are looking for and I will attempt to find it once again. Apologies in advance for this mistake, as I know I personally love reading the sources that other users provide.
10) The American Urological Association actually suggested guidelines for penis enlargement procedures as far back as 1996, which is what I based this data point off of. Published in the Journal of Urology, the guidelines were developed based on a sample size of 80 male participants and their average penis size measurements. I have two reservations about this data point: First, it’s really old. The guidelines are over 20 years old at this point, which could be argued makes them outdated. Second, the sample size that the guidelines are based on seems relatively small in comparison to the far larger studies of over 25,000-50,000 participants that we have available now. Despite these two contentions that the guidelines are outdated, I can’t find any actual reason that they should be considered inaccurate or misguided. Despite being based on only 80 participants, the data that the guidelines are based on is pretty similar to the data found on larger scales, so if it doesn’t conflict with the data that has been found in larger sample sizes, then I don’t see why it matters what data the original suggested guidelines were based on. It still holds true to similar findings today, so there’s no reason to change that. Anyway, the guidelines studied penis measurements of 80 male participants and concluded that penis lengths found outside of a certain number of standard deviations from that data’s average value should be considered “abnormal”. In other words, if you imagine a bell-curve where 95% of the male population falls within a range of penis length of, say, 4.5 to 6.5 inches when erect, then that means that only 5% of the male population falls outside that range, and presumably half of those men are on the upper end of the bell curve, which means their penises are actually longer than 6.5 inches. This leaves 2.5% of the male population that falls below the length of 4.5 inches. Since the ends of the bell curve taper off pretty rapidly, this also means that a very, very small percentage of men will far much more than about 0.25-0.5 inches below that 4.5 inch lower threshold, likely less than 0.1%. This is how the guidelines viewed and defined “abnormal” lengths, either small or large. While 2.5% might seem like a low number, consider that only about 0.34% of the U.S. population has HIV/AIDS (based on a CDC estimate of 1.1 million cases and a U.S. population of about 327 million people). That’s just one-third of a single percent of the population, or about 7-8 times lower than that previously mentioned 2.5%, yet you’ve no doubt heard quite a lot about the disease. So, for something to be considered truly medically or clinically “abnormal” or “outside of the range of normal” it has to be pretty considerably far outside that bell curve before it’s really pretty rare or unique. That’s why these guidelines suggest that only males with a flaccid penis length of less than 1.57 inches or an erect penis length less than 2.95 inches should truly feel that they are well below the average length and therefore consider penis enlargement procedures as management if they so desire to do so. Another way of thinking about this is that the guidelines suggested penis lengths that are to be considered well below average are actually about half the average length (4 centimeters versus 8.8 centimeters flaccid, or 12.9 centimeters versus 7.5 centimeters erect). Basically, unless a man’s penis length is around half of the average length or less, then he shouldn’t truly be classified as having a penis that lies well outside of the possible reasonably predicted lengths of the general male population. This isn’t to say that men who are below average but above these suggested guidelines shouldn’t be considered for penis enlargement procedures, but more so that these are the suggested lengths at which procedures are almost definitely considered viable if desired. If anyone is unhappy with their bodily appearance in any way, they should absolutely exercise their right to seek therapy, treatment, or other actions that can increase their quality of life, as that is the true goal of the practice of medicine: To increase the quality of life for everyone.
11) This is largely dependent on flaccid versus erect perception and is neither yes nor no definitively. A compiled study of three surveys found that 50.8% of men were either "satisfied" or "very satisfied" with the length of their NON-ERECT penis, while 28.6% of men reported being either "dissatisfied" or "very dissatisfied" with their NON-ERECT penis length. In the same study, 82.6% of men reported being either "satisfied" or "very satisfied" with their ERECT penis length and 71.4% reported being either "satisfied" or "very satisfied" with their OVERALL penis length (meaning, basically, "all things considered", including flaccid length, erect length, and difference/growth between the two lengths). The study also found that men were more likely to be unhappy with the circumference and appearance of their NON-ERECT penis, and more likely to be happy with appearance and circumference of their erect penis. A much larger study of over 50,000 participants showed similar results on a larger scale, with 55% of men reporting that they were happy/satisfied with their penis length, with 45% stating that they'd like to be larger and 0.2% reporting that they would like to be smaller.
12) In a survey of over 50,000 participants, 85% of women stated that they were happy/satisfied with their partner's penis size.
13) Penis length does not appear to have any effect on the rate of condom malfunction, despite having adequate sample sizes in a handful of studies. The width of the penis appears to be the primary concern related to condom malfunction.
14) Several studies have demonstrated that a larger penis circumference is positively correlated with condom malfunction rate. In other words, “girthier” penises are more likely to result in a condom malfunction. This is most likely due to the condom being stretched beyond its intended or tested specifications, meaning that condoms tend to slide off of wider penises because they do not squeeze with enough force to prevent slipping the further they are stretched, which is pretty intuitive once considered. No studies have suggested that smaller penis widths lead to increased rates of condom malfunction, however, though it is hypothesized that condoms are more likely to slide off of a thinner penis during sex because it is not gripping tightly enough around the shaft of the penis. While it has been evaluated in studies, no correlations of significance have been found to support this hypothesis, though most of the studies on this matter are thought to be inconclusive due to their low sample size and the fact that most males do not have a penis small enough to cause concerns of condom malfunction.
15) There was surprisingly little verifiable and credible information in medical literature about this from what I could tell, though there was a fair amount of literature that is more related to question #16, which is similar in nature to this one. A survey and study from 2001 conducted outside a nightclub in Mexico recorded the erect penis length of 300 male participants and surveyed participants to record reported self-measurements. This study/survey claimed that the average erect penis length was 5.88 inches, with 54% of the measurements falling between 5.5 and 6.3 inches. The study also claimed that participants seemed to consistently report lengths longer than what was measured, with most men exaggerating their penis length by 0.25-0.5 inches when allowed to self-measure. However, I am highly skeptical of this study's findings due to the lack of source credibility and lack of availability of data for review. While not technically a clinical study, an online survey was conducted that included 953 males and 762 females. The survey asked men to estimate their own penis length, but asked female participants to estimate the length of their most recent partner's penis (which I found to be an interesting method of comparing male estimates to female estimates with regards to penis size). The survey found that, globally, men estimated their penis to be 7 inches in length, while the average length reported by women was 6.61 inches, suggesting differences in perception of penis length between men and women.
16) This is similar to the previous question, but lack of measurements prohibits accuracy/honesty of self-reported data. In a survey of 52,031 male participants, 66% stated that they believed their penis was an "average" size, suggesting that most men believe they truly do have an average penis length. However, 22% of men reported their penis size as "large" and only 12% reported their penis size as "small", showing that men are more likely to believe their penis is larger than average than they are to believe their penis is below average in length. Height was positively correlated with reported penis length (taller men reported longer penises than shorter men), while weight was correlated negatively with reported penis length (heavier men reported shorter penises than thinner men).
17) One study found that 45 out of 50 women stated that "girth" or "width" of their partners' penis was more important to sexual satisfaction than penis length. Another survey of 1,500 participants found that 27% of women "care not at all" about penis length and 21% responded that they "care not at all" about penis width. The same survey found that only 8% of women "care a great deal" about penis length and only 13% of women "care a great deal" about penis width. A third survey found that 77% of women found penis length either "unimportant" or "totally unimportant", while 20% found penis length "important" and only 1% found penis length "very important". The same study found that 21% of women found length more important than girth, while 32% of women found girth more important than length, with the remaining responses either demonstrating indifference towards both measurements or equal preference toward importance of length and girth.
18) One study of 787 men and 720 women found similar scores between men and women when the International Index of Erectile Dysfunction (or "IIEF") was administered and scored. Better erectile function was associated with increased vaginal orgasm consistency for women.
19) Only one study has found a correlation between height and flaccid penis length, and while it was statistically significant in its findings, the correlation was very weak.
20) Only one study has found a correlation between finger length (the "digit ratio") and erect penis size, but the correlation was very weak.
21) A study of 104 men recorded penis length and shoe sizes of participants and did not find any significant correlation between the two measurements.
22) While most of the studies that I found had considered BMI as a potentially correlated variable with penis length, the results appeared inconsistent. Some studies suggested that there was no correlation found, while others suggested that statistically significant correlations were found, but they were weak correlations at best. Still some other studies claimed to have found correlations, but the correlations were not statistically significant, suggesting that potentially there is a correlation present but a larger sample size or more highly powered study would be necessary to detect the correlation with significance.
23) A review of a large study measuring penis length in males compared the penis lengths of homosexual males to that of heterosexual males and found that homosexual males tended to report larger penises. This has since, however, been largely refuted due to the inability to verify the accuracy of the measurements included in the study. The hypothesis for why this might be the case relies on the fact that there may have been different levels of in-utero exposure to certain hormones between homosexual and heterosexual males. Again, as far as I can tell, this has yet to be verified as a valid explanation for larger penises in homosexual male populations, and, likewise, I could not find any definitive evidence outside of this study that even suggested that longer penises in homosexual male populations has even been validated.
24) In a study of over 50,000 participants, men who reported having a larger-than-average penis were also more likely to rate their appearance more favorably. This may suggest that men with larger penises are more confident in their appearance, though it alternatively may suggest that men who are more confident in their appearance are more likely to over-estimate the length of their penis since this survey included self-reported measurements and estimates.
Discussion
Well, that was quite a trip, wasn’t it? I hope we’ve all learned something valuable and useful today, because I know I certainly have. Upon review of the scientific literature provided on this matter, I’ve come to better understand why men have the questions they do about their own anatomy, as well as why the might feel insecure about the size or shape of their penis. There’s a lot of study on the subject, and there’s a lot of data on how a man’s perception of his genitals affects his mental and emotional well-being and day-to-day happiness and satisfaction. I hope that my time here doesn’t go to waste. I hope that I could share some knowledge with someone that really needed it and enjoyed learning about it as I have. Finally, I hope we all continue learning more about our own bodies every day.
Notes
While I pride myself on my knowledge and expertise gained from my years in medical school, I am by no means whatsoever an authority on most areas in the medical field. If you believe that any of the information I've provided here is incorrect or misleading, please leave a comment detailing what you believe I've done wrong as I would much appreciate any insight into areas in which I am not as thoroughly experienced.
I hope you guys enjoy this post and share it with others here on GaG who have questions regarding the topics I've discussed here. I think it goes without saying that I spent quite a lot of time on compiling and presenting this information, and my only hope is that it reaches the screens of people who find it interesting or helpful in any way whatsoever.
I look forward to hearing your opinions and comments on the information I've presented here! Thanks in advance for all the amazing things you guys do!
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