Women are much more interested in a man's personality and looks than the size of his penis, but men can experience real anxiety even if they are average sized, according to a research review published in the June issue of the urology journal BJU International.
Dr Kevan Wylie from the Porterbrook Clinic and Royal Hallamshire Hospital, Sheffield, UK, reports that while men often have a better body image, genital image and sexual confidence if they have a large penis, women don't necessarily feel that bigger is better.
He teamed up with Mr Ian Eardley from St James' Hospital in Leeds to bring together the findings of more than 50 international research projects into penile size and small penis syndrome carried out since 1942.
By drawing together the results of 12 studies that measured the penises of 11,531 men, they discovered that average erect penises ranged from 14-16cms (5.5 to 6.2 inches) in length and 12-13cm (4.7 to 5.1 inches) in girth.
Wylie and Eardley also looked at the bizarre practices used by men worldwide to enhance the size of their penis, including the Topinama of Brazil, who encourage poisonous snakes to bite their penises to enlarge them for six months!
They report that Indian Sadhus men are known to use weights to increase the length of their penis and Dayak men in Borneo pierce the glans of their penis and insert items into the holes to stimulate their partner.
Other key findings of the review include:
· A survey of over 50,000 heterosexual men and women found that 66 per cent of men said their penis was average sized, 22 per cent said large and 12 per cent said small. 85 per cent of women were satisfied with their partner's penile size, but only 55 per cent of men were satisfied.
· Two studies reported that 90 per cent of women prefer a wide penis to a long one. Other studies pointed out that the issue of male attractiveness was complex, but that penile size was not the most important factor for women.
· Small penis syndrome is much more common in men with normal sized penises than those with a small micropenis with a flaccid length of less than 7cm (2.7 inches).
· One study found that 63 per cent of men complaining of small penises said their anxieties started with childhood comparisons and 37 per cent blamed erotic images viewed in their teenage years. None of the men studied actually had a micropenis.
· Another report based on data collected by Kinsey in the 1940s reported that, on average, homosexual men had larger penises than heterosexual men. The report authors suggest that exposure to male reproductive hormones in the womb may be one explanation.
· Individual research studies have also suggested that penis size is smaller in studies focussing on older men, but Wylie and Eardley found no overall differences when they collated the results of various studies.
· The review also provided little evidence of racial differences, with the exception of one Korean study where the men had smaller than average-sized penises. The authors suggest this area needs further investigation.
· Evidence on the effectiveness of vacuum devices, penile extenders and traction devices was found to be limited, but the authors noted that patients may experience psychological benefits from some of them.
· The review also showed that the results of surgery are poorly documented and significant complications can ensue.
"It is very common for men to worry about the size of their penis and it is important that these concerns aren't dismissed as this can heighten concerns and anxieties" says Dr Wylie.
"It is helpful to normalise the situation and provide as much accurate information as possible, as many men either lack any information or have been misinformed.
"This extensive review aims to provide clinicians with an overarching summary of the many research projects that have been carried out into penile size and small penis syndrome."
Clinicians who are presented with a man with small penis syndrome need to consider a number of treatment approaches.
"The initial approach should be a thorough urological, psychosexual, psychological and psychiatric assessment, possibly with more than one clinician involved" say the authors.
"Conservative approaches to therapy, based on education and self-awareness, as well as short-term structured psychotherapies, are often successful."
They authors are, however, very cautious when it comes to treating a psychological condition like small penis syndrome with gadgets or surgery.
"There is poorly documented evidence to support the use of penile extenders, and while information is starting to emerge on the success of some surgical techniques, this is not backed up by data on patients' satisfaction with such procedures" stresses Dr Wylie.