A new book by popular brand American Girl, from the same parent company Mattel (who recently put a transgender Barbie doll on the market), promotes blatant lies to three to 12-year-olds. 

The book, A Smart Girl's Guide: Body Image, tells children they can change sex and even how to lie to their parents about it.

A passage in the book - marketed to girls aged between three and 12 advises: 'If you haven't gone through puberty yet, the doctor might offer medicine to delay your body's changes, giving you more time to think about your gender identity.' 

It also provides a list of resources for organizations the children can turn to 'if you don't have an adult you trust'.

Whole pages are devoted to the lie that children can appropriate stereotypes of the opposite sex and claim to have changed their sex. 

No one can change their sex.

A girl cannot become a boy. She can put on a costume, make a name change, even become drug dependent (hormones), or have body mutilation surgery. But she will then just be a girl who has appropriated stereotypes via costumes, drugs or surgery. 

She is still a girl.

Binary spokeswoman Kirralie Smith said the book is dangerous and promotes lies to children.

“Puberty blockers cause great harm to children,” she said. 

“Children cannot possibly understand or consent to a lifetime of drug dependency, or their side effects such as sterility or zero sexual function.

“This book promotes dangerous lies, no one is born in the wrong body, and it is impossible to change your sex. 

“It is far better to help young girls embrace who they are and reject meaningless stereotypes, not appropriate them.”