Humans Are Wired to Doubt and Fight

First, some strange phenomena

Parents with little money went without food themselves and gave their child everything their whole life. Then the boyfriend comes along and says one thing:
"But why didn't your parents ever do that for you?"
In that moment, the one thing you didn't get starts to look bigger than the hundreds of things you did.

Work is the same. Salary, bonuses, decent benefits.
Then the boyfriend says, "Still, the boss shouldn't be hitting on you, right?"
A perfectly fine job suddenly feels unbearable.

Relationships too. They were kind and stable. Then a friend says,
"He hasn't even bought you one designer bag?" The one thing missing grows bigger than all the love received.

The strangest examples are countless. Someone who did good their whole life can have their image destroyed in an instant by one article or rumor. One bad act looks much bigger than a hundred good ones. Why?

Second, humans are naturally sensitive to the negative

Because of negativity bias, bad memories get amplified like alarms and stay longer.
One insult wrecks you more than a hundred compliments, bad rumors get more clicks than good news, and a single chance of war moves people more than ten years of peace.

A rustle in the bushes. "Probably the wind." "What if it's a predator?"
Ninety-nine times it's a false alarm. But the one time it really is a predator, the cautious one survives.

Wrongly suspecting someone harmless → you lose a little.
Wrongly trusting someone truly dangerous → you might not survive.

Suspicion creates its own evidence, worry becomes reality, and defense starts to look like attack. When two suspicious leaders face each other, a fight is bound to start. 🐍

Is that why every new president seems to end up at war?