Humanity, like all other living things on the planet, is constantly changing, adapting to its environment. People are learning to better utilize the massive amounts of brain power they have the potential to harness, developing new and interesting physical abilities. However, while a single person on their own may be intelligent, when amassed, a group mentality will take over, turning otherwise rational and sane beings into dumb and fearful creatures, willing to do anything to protect the status quo.
The human animal is beginning to adapt and evolve in ways that are not fully understood, and what people don't understand, they fear. What they fear, they lash out against. What would you do if a single mention of anything "different" about you would set off a riot or stoke a lynch mob's anger?
It's a heavy burden to carry, knowing that to be exposed is to be doomed, at the best, to life as an outcast, and more likely to be a violent end. Some will crack under the pressure while some will flourish, but all know they must keep their secret at the cost of their life; no one can be trusted with it, not even others like them, as there are those who will sell out their kind to cover their own backs.