Most 8-year old foids can handle some penetration. It depends on the depth of the vagina vs. penis size. There are cultures where it's considered normal for foids that age to be sexually active with adult men. Among the Lepcha of Nepal and Tibet, for example, old men of eighty copulate with girls of eight, and nobody minds.
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According to Ford and Beach, “Older men occasionally copulate with girls as young as eight years of age. Instead of being regarded as a criminal offense, such behavior is considered amusing by the Lepcha”. The Tontonac of Mexico invite a priest to deflower the infant girl about a month after her birth, followed by the mother's defloration of her six years later. Among the Kubeo, an old man would deflower the eight year old girl by stretching the vagina until three fingers could be inserted. (Gregersen, 1994: 291). In fact, child-adult sexual contact is institutionalized as part of initiation rituals in at least twenty countries (Konker, 1992: 148)." (
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Then I ask "why not?".
"They are too young to understand all the terrible implications of having sex", is usually the answer.
This begs the question, "what terrible implications and why not?".
Lets explore the terrible implications.
The terrible implications refer to trauma, since as long as you respect the child's boundaries, there are no immediate negative consequences to sexual activity. If no coercion is involved, there will be no problems until the child realizes that what happened is "wrong", which often takes many years. Until then, the child is no different from other children.
The issue here is sociogenic and iatrogenic harm.
People who have sex as kids don't automatically feel trauma! It's up to society and psychologists to being them around to the socially approved way of seeing things, so they can seize the trauma narrative as their own.
Another way to view it is as re-education and brainwashing, particularly for those who didn't initially view themselves abused. The patient is viewed as damaged so long as he or she does not attribute trauma to their experience. Once they understand the trauma, once their understanding rights itself, the patient is on their way to recovery and becomes a "survivor".
Children are allowed to consent to sex and sex play with other children. In fact, most child psychologist view sex play as beneficial, and while the child should be taught that sex should not be forced upon them or anyone else, they think children should be permitted to engage in safe and "age appropriate" sex play.
So the dominant view it is not "children cannot consent to sex", but "children cannot consent to sex (or sexual contact) with someone who is more than X years older than them", even though a sexual relationship between a young child and an adult is unlikely to be harmful if the adult takes steps to ensure safety and to make sure that the child is willing.