When 8-year-old Etienne Melese went toy shopping, he blew right past the trucks and swords and went straight for the dolls.
Etienne knows this makes him different from many of his male classmates.
"They think that a real boy has to be really tough and can't do anything that's not tough," said Etienne, who says he is teased by other kids and describes recess as "terrorizing."
At a very young age, boys learn they are expected to play with trucks, toy guns and other masculine toys, while girls stick to dolls, dress-up and house. But not all boys prefer GI Joe to Barbie — and those who deviate from the expected behavior may find themselves the subject of ridicule.
"Boys are still in what I call a gender straitjacket," said William Pollack, a Harvard psychologist who has studied children's behavior for years.
Males are expected to follow "the boy code," Pollack said.
"There's a very narrow definition of what acceptable masculinity is about," he said. "We are scared to death if a boy moves out of that, he won't grow up to be a real healthy man."
The Boy Code
As an unscientific experiment, ABCNEWS' 20/20 assembled several groups of boys and girls ages 4 to 8 to see how they would behave in a room filled with both "boy" toys and "girl" toys. The boys generally gravitated toward the masculine toys, while the girls, too, chose toys associated with their gender. If a girl chose a "boy" toy, the other children did not seem to care. But when offered a "girl" toy, most of the boys strongly rejected it.
Pollack said the experiment illustrated how "the boy code" affects children's play.
Male babies are actually more emotional and attached to their mothers than girls, said Pollack, but their natural "gentleness" is overwhelmed by social pressure to be strong and macho.
"It is not abnormal for a boy to want to play with things that we call girl things. We think that there are so many differences between boys and girls that we forget that we're one species and we live on one planet," he said. "And it's we adults who early on start pushing boys and girls to be more different than they need to be."
Boys, he said, "like all human beings, have a sensitive, gentle part to them. It's just that with boys and men, we're less likely to let them express it."
If boys were allowed to be sensitive and gentle, said Pollack, they'd likely grow up to be happily married men and nurturing fathers.
"If we have more loving, caring men in America," he said, "that wouldn't be an illness. That would be a solution to many of our problems."