The size of the penis varies significantly between individuals, particularly in how much it changes from a relaxed, or flaccid, state to an erect state. The terms “grower” and “shower” are informal labels used to categorize this observable difference in the ratio of size change. This difference is a common biological variation and is not recognized as a medical condition or classification.
Defining Growers and Showers
The difference between a grower and a shower is based on the magnitude of length increase when the penis transitions from flaccid to erect. A “shower” is a term for a penis that is already relatively long in its flaccid state and experiences a minimal increase in length upon erection. Scientific studies sometimes define a shower as a penis that increases by less than \(31\%\) in length. This means the erect size is not significantly larger than the resting size.
A “grower,” conversely, refers to a penis that appears smaller when flaccid but undergoes a substantial increase in length and girth when it becomes erect. Researchers often categorize a grower as a penis that expands by more than \(56\%\) from its flaccid length. In absolute terms, some studies use a cutoff, defining a grower as one that increases by \(4.0\) centimeters (\(\sim 1.5\) inches) or more. The majority of individuals, however, fall into a middle category, experiencing a moderate degree of growth that places them between the two distinct labels.
The Underlying Physiology of Size Change
The mechanism behind this variation lies primarily in the composition and elasticity of the penile tissues, particularly the tunica albuginea. This is a dense, fibrous sheath that surrounds the corpora cavernosa, the two main chambers responsible for achieving an erection. During an erection, blood flows into the corpora cavernosa, causing them to engorge and expand.
In individuals identified as growers, the tunica albuginea tends to be more compliant and elastic. This tissue characteristic allows for a greater degree of stretching and expansion when the cavernosal bodies fill with blood. The smaller flaccid size may also be related to a lower volume of residual blood maintained in the corpora cavernosa at rest, which creates a larger capacity for influx during arousal.
Showers, on the other hand, often maintain a higher baseline volume of blood in the corpora cavernosa even when flaccid. This results in a larger resting size but leaves less room for dramatic expansion during engorgement. The fibrous tissue in a shower may be less elastic, limiting the overall change ratio between the flaccid and erect states.
Factors Influencing Flaccid Size Variation
While the grower or shower tendency is an inherent anatomical trait, the flaccid size itself is highly susceptible to temporary environmental and physiological factors. These external influences can alter the perceived ratio of change. The most significant external variable is ambient temperature.
Cold temperatures cause vasoconstriction, a narrowing of the blood vessels, which reduces blood flow and volume in the penis. This results in a smaller, more retracted flaccid state. Conversely, warmth promotes vasodilation, increasing blood flow and leading to a longer, fuller flaccid size.
The body’s stress response also plays a role, as the release of adrenaline and noradrenaline triggers a reflex known as penile retraction. This physiological reaction causes smooth muscle contraction within the penis, temporarily decreasing the flaccid length. Factors such as anxiety, physical activity, or even the level of arousal preceding an erection can therefore temporarily influence the resting size.
Dispelling Common Misconceptions
One of the most persistent misconceptions is the belief that flaccid size is a reliable predictor of erect size, or that being a grower results in a larger maximum length. Scientific data, however, indicates that there is no correlation between the flaccid size and the length achieved during a full erection. A smaller flaccid penis may ultimately reach the same erect length as a larger flaccid penis.
The average erect length across various studies is consistently reported to be around \(13.12\) centimeters (\(\sim 5.17\) inches). A penis that is a shower is just as likely to fall into this average range as one that is a grower. The distinction is merely cosmetic and does not affect the maximum size, sexual function, or the capacity to experience pleasure.