I think it's very telling that the boy in light blue at 1:45 was confused by the question his mom proposed. Even just having lived for a very short amount of time you can make observations and see that things are what they are. At that point in his life it was like asking him what if I told you the sky was yellow. His little brother however seemed to not even care to be there. At this point in his life he is an empty vessel that can be filled with whatever you want. Minds are very malleable at a young age. The boy in light blue actually seemed confused throughout the rest of the video but with enough enforcement he can easily be brainwashed as well.