Plenty of people go on saying that if aliens were to invade us, we'd show them who's boss.
While that is debatable, we are aliens amongst ourselves.
Everybody has a different belief, different vision, different perception regarding the well-being of life.
If you go by religion and religious people, men and women have to be straight, women have to obedient to the man, and they are not allowed to go over his word. Also, everybody that happens and will happen, it'll be because of a deity, depending on which religion you follow. That's the cool thing about it. The indoctrination differs from continent to continent, and country to country. Heck, from area to area. And some countries want to be blessed by that deity more than others. Probably why they're losing their minds.
If you go by race, white people think they can rule everyone by virtue of... Europe? Because they have the most documented things whereas Africans don't, and Asians are in the East, so they don't matter as much. As they speak that weird language, too. That is, until the last twenty odd years, when some of them have gained some clout. Or have been allowed to gain it. Hispanics haven't gained much of it, unless they were born in specific white countries.
If you go by politics, you have right and left wing, and then you have extremists, who, some of them, are still led by religious beliefs. Others believe in certain regimes, like communism, stalinism, or nazism...
The Earth is round, but there are plenty who still believe it's flat.
People are homosexual, transexual, and a few other sexual, yet the general population thinks they're defective, mentally ill, and some think they deserve to die.
Society wants you to look good, have a toned body, and work like a robot, but then it created fast food, junk food, bad food, and it pushes it to the point where you don't know what to do anymore. Perceived flavour versus actual taste and actual nutrients. Hard decisions that make your tire before you end up doing more worthwhile things.
Before we conquer planets, we should find peace between us.