Negativity Bias
Bad is stronger than good — your brain weighs one insult heavier than five compliments, and that math runs whether you like it or not.
Grounded in the research on negativity bias
so why does one bad comment ruin my whole day?
Because bad is literally stronger than good. Roy Baumeister and crew laid it out in 2001 in a paper actually titled "Bad Is Stronger Than Good" — negative stuff hits harder, sticks longer, and out-muscles equal-sized positives. Five nice replies and one nasty one, and guess which one you're replaying at 2am.
is my brain broken or what?
Nope, working exactly as designed. Paul Rozin and Edward Royzman (2001) called it negativity dominance: mix good and bad and the bad drags the whole thing down past where the math should land. It's not a glitch, it's the default — your nervous system rounds down on purpose.