The age of consent was the fault of homophobic feminists
The age of consent was raised from 13 to 16 in 1885 in the very same bill that criminalised homosexuality. It was the result of campaigning by puritanical anti-sex feminists who essentially believe that 'All sex is rape'.
13 year olds are mentally perfectly capable of understanding the consequences of their actions to the required level as they have already lived longer than the life expectancy of many animals (e.G. Dogs, cats) most of whom would reproduce at a much younger age.
Not being allowed to have a sexual relationship at a young age can result in an increased risk of lifelong celibacy and failing to have any offspring at all (women have a biological clock, you know). This can of course result in depression and suicide.