Vigilance at night to guard against arctic predators, hoarding during thaws to stock the cave with as much as possible without much concern for organization until later, frequent releases of frustration with colourful pejoratives with little regard for social mores.
I knew all this stuff already.
Sapiens is concerned with appearances and perceptions. Neanderthals are only interested in results. One is adapted for warm weather. The other adapted to live on Earth. Guess who wins this one in the end. No wonder Sapiens desperately needs to believe in global warming. The alternative is extinction for his genes.
Survivalists, I got the M. Night Shymalayan ending for you. Do you know how your whole life almost everybody around you keeps insisting that only people suffering from mental illness are interested in being prepared? The twist at the end of the movie is ... CT Scans of the brain reveal everybody else is nuts except for survivalists and people of similar genetic bent. Neanderthal doesn't need to explain, he is the longest surviving hominid on the planet and was adequately debugged a hundred thousand years ago or earlier. The reason Neanderthals are vigilant about the future is that they are extremely intelligent, farsighted and always on top of their game even when everybody else around them is blowing bubbles and waiting for the secular paradise. There is no plan B other than Neanderthal genes. All others are botched and bungled.
There's poetry in cursing and calumny and different kinds of language play in vituperation that are essentially a way to turn anger and fear into a sort of comic relief. Once again, a creature who manages to spin gold out of lead every time no matter what the situation. When the problem has been properly insulted then the return to problem solving is likely to follow.