When a core belief is challenged with contradicting evidence, people sometimes dig in and believe it even more strongly.

* Challenging an identity-linked belief can trigger counter-arguing that leaves the person more convinced than before. *

The mechanism is identity-defence: a belief tied to who we are feels like part of us, so an attack on it is processed as an attack on the self. Instead of updating, we spend mental effort generating counter-arguments and rationalisations — and that effort strengthens the belief, leaving us more entrenched than before.

Example: Showing someone a thorough fact-check that debunks a rumour they're invested in can leave them more convinced of the rumour, because they marshalled reasons to dismiss the correction and reinforced the original belief in doing so.

Tip: Facts alone rarely move identity-linked beliefs. Lowering the stakes ("you're not stupid for having believed this") often works better than piling on more evidence.

Go deeper:

• Wikipedia — Belief perseverance — why beliefs survive their own disproof (covers the backfire effect).

The tendency to see the past in a positive light and the future in a negative one — to believe society is in decline.

* The nostalgic gap: a felt sense that things are getting worse runs opposite to long-run data that they are improving. *

The mechanism is partly memory (we remember the good and forget the bad of earlier times — see the fading of negative affect) and partly negativity bias applied to the present and future, where ongoing problems are vivid while progress is gradual and unnoticed. Every generation tends to believe its own era is uniquely going downhill.

Example: "Kids today have no respect and everything's falling apart" is a complaint recorded in nearly every era for thousands of years — which is a strong hint the feeling tracks a bias, not an actual unbroken multi-millennial decline.

Tip: Nostalgia is a poor measuring stick. When you sense things are "getting worse," check it against actual long-run data rather than the rosy glow of memory.

Go deeper:

• Wikipedia — Declinism — rosy retrospection and the psychology of 'the good old days'.