Forgive and forget is advice that has been passed down through generations of peacekeepers, television sitcoms and films, and sage mothers from my adolescence and well into adulthood. But is this adage as easy as it sounds? Forgive? Maybe. Forget? Never. 

We Can't Let Go of Grudges

More than three decades later, I have yet to forgive or forget the boy who taunted and terrorized me in elementary school, calling me names and insulting me during recess period.

Or the pair of old men who casually grunted racist slurs then laughed at my friends and me, a group of high school girls, innocently enjoying a night out on the town. There was also that time a good friend promised he’d come to an important event but failed to show up.

He’s reached out since to apologize, but I still can’t bring myself to rekindle our friendship.

To you and me both, these are petty, trivial transgressions in the grand scheme of things.

Yet, as these memories resurface, the hurt and anger they elicit still feels as fresh and raw as when they first occurred.

If these are the insignificant, trivial villains from my past, imagine how I must feel about those who have wronged me in deep, more consequential ways.

And Grudges Are Like Inexcusable Crimes

Suffice to say I am hardly the only person who happily clings to resentment. As it turns out, I, too, have been on the receiving end of a grudge.

I’ve wronged others, sometimes unwittingly, and my offenses have yet to be forgiven nor forgotten.

A former friendly acquaintance from a decade ago reached out to me not too long ago, accusing me of betraying our friendship by dating someone she had been interested in.

It didn’t matter that I remembered both the story and our supposed friendship differently.

To her, I had committed an inexcusable crime, one that had birthed a grudge so potent, that after a decade of silence, it imploded into a furious torrent of angry Facebook messages, spewing with absolute conviction that I was the worst person on the planet. Clearly, the past was far from forgotten. 

Grievances Breed Hostility and Anger, as Well Physical Illness

Science tells us that holding onto hate, or any kind of negativity, for that matter, hurts our mental and physical health and our happiness.

Yale professor Marc Brackett explains in a Medium post, negative emotions, such as “anxiety, anger, sadness, and stress are closely associated with unhealthy behaviors, such as poor diet, smoking, excessive drinking, physical inactivity, and social isolation,” factors which can lead to heart disease, cancer, Type 2 diabetes, addiction, and dementia.

Hostility and anger, in particular, are often linked to heart disease. He notes that “men reporting the highest levels of anger were two-and-a-half times more likely to suffer cardiac events [e.g., heart attacks] than other men.”

There are no upsides to holding onto negativity, but despite this clear logic, we often refuse to let our grudges go. Is it that we’re taught to be vindictive or is it inherently in our DNA? 

Origins of the 100,000-Year-Old Grudge 

Dr. Penny Spikins, an archeologist at the University of York seems to think that it’s the latter.

In fact, she believes the ability of early humans to hold a grudge is what catalyzed populations to spread and grow, ultimately resulting in the modern world as we know it.    

The earliest humans migrated very slowly and were largely limited by environmental barriers.

But 100,000 years ago, she says, something shifted within social relationships.

As humans began to rely more on each other for survival, they also became more inclined to identify and punish those who betrayed them. And thus, a ‘dark’ side of human nature was born.

Eventually, these “moral disputes motivated by broken trust and a sense of betrayal became more frequent and motivated early humans to put distance between them and their rivals.”

If a group of people is seeking to take revenge against you, it could be “strong motivation to get away, and to take almost any risk to do so,” says Spikins.

Individuals would leave their communities in search of new allies in distant places. Lacking many choices, these early humans who had once lived comfortably in the grasslands and open woodland in Africa and Asia were suddenly forced to migrate to more “distant, risky and inhospitable areas” into Northern Europe or across the sea to Australia and the Pacific islands to stay out of harm’s way. 

Spikins’s research illustrates how resentment played a pivotal role in growing and developing the world’s population, cultivating an evolutionary trait vital to our survival. However, it doesn’t answer one, basic yet important question. 

Why do grudges make us feel so good? Or rather, why is that so many of us can empathize with Madeline Martha Mackenzie from Big Little Lies, who embraces this complicated emotion with glee: “I love my grudges. I tend to them like little pets.”