Encouraging young girls to look sexy can have an adverse impact on their schoolwork. And marketing Playboy stationery and lacy underwear at prepubescents can also make them more vulnerable to paedophiles, the Scottish Parliament heard this week.
So teachers have a duty to ensure that children develop a healthy view of sexuality, distinct from this porn version being marketed in shops, according to Jessica Ringrose, a feminist academic at the Institute of Education in London.
This week the Scottish Parliament's equal opportunities committee discussed the increasing sexualisation of products aimed specifically at children.
They looked at the growing trend for "sexy toys" aimed at the children's market. These include pink Playboy bunny stationery, as well as thongs for prepubescent girls, Bratz dolls, and a children's bed with the brand name Lolita.
And they examined the effects of these sexualised products on girls. Evidence from the American Psychological Association suggests that such products lead to "self-objectification" - when children begin to value a sexily attractive physical appearance above all other personal qualities.
The association also points out that such self-objectification can have a severe impact on pupils' academic achievement.
Researchers asked girls to try on a swimming costume or a jumper in a private dressing room. While waiting, they were asked to take a maths test. The girls in swimming costumes scored less in the test than those in jumpers.
The researchers said: "Thinking about the body and comparing it to sexualised cultural ideals disrupted mental capacity."
Girls who objectified themselves were less likely to use condoms or to be sexually assertive.
The committee also heard evidence from Tom Narducci, of the children's charity NSPCC. Mr Narducci told them that young girls in push-up bras and T-shirts with lascivious logos "give paedophiles a greater ability to justify the abuse of girls, because they can say, `this is a sexualised girl'."
And Agnes Nairn, a marketing expert, said exposure to sexual imagery makes children more vulnerable to paedophiles.
A young girl, for example, could look sexually precocious by mimicking provocative dance moves on music videos.
But Dr Ringrose believes that the issue is more complicated than these reports would suggest. She argues that, from a psychoanalytic perspective, children are already sexualised: they have sexual hierarchies and sexual fantasies. The idea that they are innocent, sexless beings originated with the Victorians.
"The debate is around children," she said. "But actually we need to look at the commodification of the female body.
"It's a very specific form of sexuality that's being imposed, on children and adults: a porn version. This is what kids are dealing with on a daily basis. It's how kids are supposed to be sexy."
She therefore believes that personal, social and health education lessons need to address the gulf between porn-influenced, commodified sexuality and the more realistic version.
"If we're saying there's a pornification of society, schools need to engage with it," she said. "We need to have a much broader sex-education curriculum, to engage with issues of sex and power. Because it's massively impacting the global economy."