The main problem is that the child has usually no experienced
person with whom he can discuss these matters, another the poor
quality of usual pornography.
Observation of Others
The observation of sexual acts is a widely distributed possibility to get information about sex. Especially parents are often observed - with or without (through the keyhole) their permission.
IMO, it is more dangerous if the child is seeing the sexual act
without permission and knowledge of the parents and without having the
necessary information what happens. It may misinterprete the
intercourse as an act of violence and has no possibility to ask.
Almost all boys and the majority of girls
masturbate. This allows
children to get some experience with the own body.
Sex Plays With Peers
Pedosexual Relations and Sex Education
In sexual relations with adults
children can also learn a lot of things about sex.
Sex Education in Different Cultures
Sex Education and Animals