Our ingrained tendency to destroy, ...especially each other, and the ignorance, prejudice, pride and greed that drives that tendency.
Lots of good answers but everybody has missed the biggie.
If we don't restrain ourselves somewhat the population will speedily outstrip the planet's capacity to sustain life. Currently there are 7.3 billion people huddled on this big, blue marble; by 2100 (and that's only 80 years away -- some of you will still be alive) it's expected to reach 11.2 billion. And after that? Scary stuff.
Their desensitization to violence. About 10 or 15 years ago I used to be greatly affected by stories of violence on the news. I'm kinda numb to it now cos I see it so often. That scares me.
No regard for human life ! They like to kill one another way too easily and many with no remorse whatsoever.
Unpredictable reactions to survival. It takes a lot of time and effort to make sure someone will not turn against you for their own survival and sake.
A prefect scene with a marvelous meaning from the TV show, The Walking Dead:
There's a father who's having a hard time to accept this walkers and half alive humans who eat human flesh. He can't accept scientific reasons only religious and god says. So he's so disappointed and looking for answers. There's a place where he goes to (according to film) something had happened there, he wanted to witness the scene and observe, he goes there, he finds bible, he finds bible and he feels like he can guide people with this, it's like he found the answer! The peace, (as he battling for his own faith) few steps upon the ground, he finds a half of a human leg it's been cooked and almost eaten (by other people, human being) this is what people come to even do for surviving. Eating each other to stay alive. Now you wanna guide these people with bible ? Never gonna work.
No love for family or country. Very very quick to kill and kill lots of people, no reason. Just because!
I agree with Rooster. 2 recent murders here, 2 separate incidents two men killed 8 members each of his families. From 1yr-15yr. Most were shot and stabbed.
Our capacity for violence is frightening.
The most scariest? I find that humans are way too capable of violence and destruction. And that sucks.
Great question and u have great answers here
I always come back to the scene in "The Matrix" where the Agent is along with Morpheus and is comparing the human race to a magligant viris. ,
A lot of the answers here seem to point to the existence of a "stupid"
A lot of these other problems that people mentioned here are due to racism and Discrimination.
Also, humans tend to get upset too easily, and when they get their feelings hurt, they tend to like to show others not to mess with them, and this is how some wars are started. A way to solve this problem, Is to realize, we are human. Not everyone is going to say what you would like to hear. It's best to take what the other said, and not get upset, and if it's a fault, you can work on that to better improve yourself as a person!
A way to solve the racism problem is to realize, Everyone is created equal, whether Black, White, Mixed, Asian, Hispanic, Any combination of the above, or any other races out there.
I think if our society just uses common sense, we would have very minimal issues!
Our ability to judge and hate one another based on knowing nothing about the other person.