The Recipe for a Grudge

The Recipe for a Grudge

Earlier this year, researchers in Canada published something I keep coming back to.

They wanted to know what a grudge actually is, chemically — not the philosophy of one, but the emotional ingredients that make a hurt turn into a held thing. Across several studies, they figured out the recipe.

There are two ingredients. That is it.

Ingredient one: hurt. The "I trusted you and you cost me something" kind. The wound part.

Ingredient two: anger. Not the explosive kind. The slow kind. The kind that simmers.

By themselves, neither one creates a grudge. Hurt without anger fades into sadness. Anger without hurt fades into a story you tell at dinner. The two together — that is the recipe. And once they combine, something specific happens in your head.

You stop seeing the person as a person who did a bad thing. You start seeing them as a person who is fundamentally bad. Not "she let me down that one time" — "she is the kind of person who lets people down."

Once that switch flips, letting go feels different. It feels like moral failure. Like you are making excuses for someone who is genuinely a bad actor. The grudge becomes righteous. That is the part that locks it in place.

I read this and felt seen and a little embarrassed.

What the tally was costing me

While I was sitting with that, I went looking for the rest. The body's bill on a held grudge. Here is what people have found.

People who hold grudges report more anxiety and depression than people who do not. That comes from work out of a university in Rome. It is not a small effect. It shows up consistently across samples.

Holding grudges raises stress. Stress raises cortisol — a hormone the body releases when it thinks something dangerous is happening. Cortisol over a long time disrupts sleep, weakens the immune system, raises blood pressure, and slowly inflames the body from the inside. The grudge does not know the threat is years old. The body just gets the signal.

Your body cannot tell the difference between a memory and a present danger. It just gets the alarm.

There is one finding that genuinely stopped me. Researchers tracked a large group of older adults for ten years. The people who scored high on hostility and cynicism — the personality flavour grudge-holders tend toward — showed measurably more cognitive decline over the decade than people who reported regularly forgiving themselves and others.

Ten years of holding things makes you forget faster. That is what the data said.

The other thing it costs

There is a smaller study from a few years earlier that I keep thinking about. Researchers found that people who hold more grudges are also more socially isolated — and the direction of cause runs both ways. Holding people at arm's length predicts more grudge-holding later. Holding more grudges predicts more isolation later.

The tally does not just cost you closeness with the people on the list. It costs you closeness in general. Once the basement is full, you start letting fewer people into the house.

That is what I think Sulla missed. He bragged about repaying friends and enemies in equal measure. He died with very few of either left. The line on the tomb makes it sound like a closed circuit. The closed circuit was the problem.

So: the recipe is two ingredients. The bill comes in stress, sleep, blood pressure, and over enough years, memory and closeness.

But knowing the bill does not make it easier to stop. I tried, while writing this, to just decide to drop one of the items in the basement.

It came back the next morning, in line at a coffee shop, completely uninvited.

Which raises the question of what is actually happening when a tally refuses to leave.

References

• Li, J. S., et al. (2026). The emotional recipe of grudge-holding: Hurt, anger, and moral character judgments. Personality and Social Psychology Bulletin. Coverage: psypost.org
• Toussaint, L., et al. (2018). Forgiveness, hostility, and cognitive decline. Discussed at: americanbehavioralclinics.com
• Sapienza University of Rome — study on grudge-holding and depression, discussed in the same source.
• Karremans, J. C., et al. (2016). On grudge-holding and social isolation. Cited at: healthline.com