DIANE SAWYER: (Voiceover) Dr. Marjorie Hardy, assistant professor of psychology at Muhlenberg College in Allentown, Pennsylvania, who has conducted a number of clinical studies with children and guns.

Dr. HARDY: It does not work to tell kids what to do.

SAWYER: (Voiceover) With her advice, we decided to set up an experiment of our own. We went to this day-care center in Allentown and rigged a playroom with three hidden cameras. We filled the play area with all kinds of toys and with something else, three handguns, a .38, a .22, a .357 Magnum, all of them real but unloaded and disabled. We placed them at varying times on a table, in a small purse and in a box of toys. Dr. Hardy said young kids don't make a distinction between a gun they'd find in an adult closet or shelf and one they'd find in a toy box.

Next, with their parents' permission, we recruited 40 children, ages three to 10. We took half of them and assembled them four days before our experiment for a powerful lecture about the dangers of guns.

Lieutenant JOE HANNA (Allentown Police Department): Are real guns toys?

Unidentified Child #5: No.

Lt. HANNA: No.

SAWYER: (Voiceover) The lecture was given by Lieutenant Joe Hanna of the Allentown police.

Lt. HANNA: And you can never play with guns,

SAWYER: (Voiceover) Lieutenant Hanna had help from someone else.

Lt. HANNA: Now I'm going to show you a very short videotape.

SAWYER: (Voiceover) His name is Eddie Eagle, a cartoon character, star of a seven-minute video created by the National Rifle Association. And what does Eddie Eagle tell kids to do when they see a gun?

(Excerpt from NRA video)

SAWYER: (Voiceover) The NRA has sent Eddie Eagle to schools around the country, and claim that his warnings do make a difference, a way to have your gun and safety, too.

SAWYER: (Voiceover) But what about the children who had been present for that lecture, the kids who were told never to touch a gun?

Unidentified Boy #7: (Points gun at his friend and make shooting noise)

Unidentified Boy #8: Don't shoot me.

SAWYER: (Voiceover) Well, here's one of them, a three-year-old...

Boy #7: (Points gun at his friend and makes shooting noise)

SAWYER: ... ignoring his playmate's pleas for mercy.

Boy #8: No, don't shoot me anymore.

Boy #7: (Again points gun at his friend and makes shooting noise)P> Unidentified Mother #5: He was somewhat being cute, but I was stunned inside and scared.

SAWYER: (Voiceover) This mother said they have no guns, not even toy ones at home.

Mother #5: He was so natural with it. It looked like he played with it every single day. And it was scary when he played dead. I became numb.

SAWYER: (Voiceover) We were amazed at how many children who had watched that Eddie Eagle video talked the talk. Listen carefully to these boys.

Unidentified Boy #9: Do you know what to do when you see a real gun?

Unidentified Boy #10: No-

Boy #9: Stop, don't touch, leave the area and tell an adult.

SAWYER: (Voiceover) But moments later, their caution was blown away in a hail of pretend bullets.

Boy #9: (Points gun at his friend and makes shooting noise)

Boy #10: Bam, I shot you.

Boy #9: (Pretending to shoot gun) Poo!

Unidentified Mother #6: It makes me nauseous.

ADAM (Three Years Old): Look, I found a gun.

SAWYER: (Voiceover) And meet three-year-old Adam, another child who remembered what he'd been told.

ADAM: But we can't--hey, don't touch it. Don't touch it! Don't! Don't touch it!

SAWYER: (Voiceover) When Adam saw the gun, he sounded the alarm, but his playmate was undeterred, even though he'd been at our warning lecture, too.

BRAXTON: Watch out. Ah.

SAWYER: And a few minutes later, Adam had apparently decided if you can't beat them...

ADAM: I can hold it.

BRAXTON: Another one.

ADAM: Yeah.

BRAXTON: Another one.

ADAM: (Picks up gun and makes shooting noise)