This was told to me by Sandy and Darryl Bem, both of whom are Psychology
Professors at Cornell University.

The Bems, being well-versed in the area of sex roles and psychology, had
decided to raise their children androgynously. This included not only the
typical male-toy/female-toy aspects, but they were also very careful not to
impose any of their own learned sex role socialization upon their children.
For example, a frequent phrase was the only difference between a male and
female is that a male has a penis and a female has a vagina. When the
parents were asked whether a person that the child could see was male or
female, they would reply (even if the parents could tell which it was), I
dont know, dear, they have pants on, so we cant see if they are male or
female.

One day, their son (then in Kindergarten) decided that he wanted to wear
hair barrettes to school. Sandy and Darryl, of course, acquiesced and put
barrettes in his hair.

That night, they got a phone call from his teacher (who knew about the Bems
rearing plan), who related the following story:

Upon arriving at school, another boy came up to their son and asked why he was
wearing barrettes in his hair. Little Bem replied, Because I felt like it.
The other boy was visibly upset at this, but walked away.

A little while later, the boy comes back and says, Why are you wearing
barrettes in your hair? Only girls wear barrettes; you must be a girl.
Bem, true to his upbringing, replies, I am not a girl; I have a penis and
testicles, girls have a vagina. The boy once again walks away.

During recess, the boy comes back once again, and insists that Bem is a girl
because he is wearing barrettes. Once again, The only difference between
boys and girls is that boys have a penis and testicles and girls have a
vagina.

The little boy exclaims, You must be a girl; youre wearing barrettes.
But Bem replies, Im a boy; I have a penis and testicles. Look–Ill show
you! At this point, Bem pulls down his pants to prove that he has a penis
and testicles…

The boy replies, Everybody has one of those, but only girls wear barrettes.