This is a lie pedophiles want you to believe and that the manosphere purports as fact to support all their predatory behavior toward underage girls. The average age of marriage has always been above 17 worldwide, and typically over 20.

http://www.todayifoundout.com/index.php/2014/02/teen-girls-stop-commonly-getting-married/

It may have been legal in many countries to marry at 12, but it has by no means been the norm. 12 year old girls can’t even healthily carry a pregnancy to term, births before 16 have high rates of mortality which even people thousands of years ago knew.

Even in the Democratic republic of Congo, which is known to have some the lowest ages of average marriage in the world, only 10% of girls are married off before age 15:

https://en.wikipedia.org/wiki/Child_marriage_in_Democratic_Republic_of_the_Congo

This pattern is observed worldwide in all of the countries that still allow marriage under the age of 18. No more than 15% of girls are married before age 15, and no more than 40% before age 18. Which, still makes the overwhelming majority of marriages for women occurring after the age of 18 even in the most oppressive environments:

https://data.unicef.org/topic/child-protection/child-marriage/

Furthermore, these girls are typically married to boys close to their own age, huge age gaps are ALSO not common. 40% of girls are married before the age of 18 in central Africa, but so are 28% of Boys.

So any of these adult scrotes justifying their attraction to adolescent girls with "Muh bIolOGY" are pedos, end of story.