Fact check: What are the average penis size changes from adolescence to adulthood?

1. Summary of the results

The average penis size changes from adolescence to adulthood are not directly quantified in most of the analyses provided ^{[1] [2] [3]}. However, a cross-sectional study of 2,974 Chinese boys ^[4] shows a gradual increase in penile length up to age 10, followed by a sharp rise between ages 11-15, and then a plateau after age 15. For example, the mean stretched length at age 12 is around 9-10 cm, rising to ~12 cm by age 16 ^[4]. Another study of 6200 white males aged 0-19 years from Bulgaria ^[5] indicates that penile length and circumference demonstrate gradual growth since birth, with peak growth between 12-16 years of age. A prospective cohort study ^[6] also shows significant increases in penile size across all intervals, with the highest growth rates occurring between the first and second years post-bone fusion. The pooled mean penile lengths across all ages from 75 studies (55,761 men) are: flaccid 8.70 cm, stretched 12.93 cm, erect 13.93 cm ^[1].

2. Missing context/alternative viewpoints

• The original statement lacks specific age-related data on penile size changes from adolescence to adulthood, which is provided by some of the analyses ^{[4] [5]}.
• The focus of some analyses is on secular trends in penile length ^{[1] [2]} rather than individual developmental growth, which might be more relevant to the question.
• The importance of hormonal influences on genital development, including penile size, is mentioned ^[7], but not explored in depth in relation to the question.
• Different populations are studied, such as Chinese boys ^[4] and white males from Bulgaria ^[5], which might have different growth patterns.
• The definition of adolescence and adulthood can vary, which might affect the interpretation of the results (no specific source provides this context).

3. Potential misinformation/bias in the original statement

The original statement might be misleading because it implies that there is a straightforward answer to the question of average penis size changes from adolescence to adulthood, when in fact, the analyses provided show that this information is not readily available or is population-specific ^{[1] [2] [3]}. The Stanford news article ^[2] and the systematic review ^[1] focus on the trend of increasing erect length over the last 30 years, which might not be directly relevant to individual growth patterns. The studies that do provide age-specific data ^{[4] [5]} might benefit researchers and healthcare professionals interested in understanding normal growth patterns, while the general public might be more interested in the overall averages and trends ^{[1] [2] [3]}.