The average penis length has increased over the past 30 years, a new study has revealed, but experts warn it might not be the ideal reality every man’s dreamed of. Researchers discovered that the average penis size had grown a staggering 24% over nearly three decades. Past research has linked smaller penis size to pollution, but now experts believe toxin exposure can cause them to become enlarged. But the deep dives on penis size have been criticized for preying on male insecurities, specifically as it relates to infertility. This is a very novel idea but the study does not tell us what a normal penis length is,” she added.