By Emiliana R Simon-Thomas, Greater Good Magazine

Research suggests that holding a grudge affects the body in ways that can undermine your health, while forgiveness may help restore balance.

Humans are wired to recoil from loss, whether we lose a coveted resource, our sense of self-worth or honor, our personal safety, or something else. Feeling averse tells us to avoid whatever, wherever, or whoever is connected to the pain of losing what’s important—including someone who hurt us.

But as time passes, is it helpful to hold on to feelings of distress or ill will? While avoiding someone, stonewalling them, or plotting revenge can feel natural, are the feelings that drive these kinds of reactions good for health and well-being in the long run? 

Research suggests not. Letting go of anger and extending goodwill to the people who harmed us tends to restore our internal equilibrium and help us sleep better and live longer.

But why do some things still feel unforgivable—like holding a grudge is the right thing to do? 

Forgiveness and the nervous system

The human body is built with two main branches of the nervous system that are below the neck: the sympathetic branch (SNS) that mainly supports faster “fight or flight” drives and reflexes, and the parasympathetic branch (PNS) that is more involved in gradual “rest and digest” and “tend and befriend” motivations and behaviors. These systems are in constant dialogue, dynamically shifting physical resources like oxygen, glucose, and hormones back and forth to equip us to do whatever is best for our survival in any situation.

When we sense threat or are reminded of something hurtful, the SNS is dominant. When we feel safe and beloved, the PNS prevails. It feels right when these systems give us the energy, wherewithal, and focus to do the right thing, like hustling to catch a bus, train, or airplane when we’re late, or enjoying a deep, loving conversation with a friend after a nice meal.

Sometimes, though, there’s a mismatch, like late-night restless worrying even in the comfort of a safe and warm bed, or procrastinating on an important, time-sensitive task. Mismatches often involve miscalculating time, either focusing on the short term when a long-term view would be more helpful, or ignoring the present moment in favor of the unchangeable past or unknowable future. The “negativity bias,” which is our mental tendency to privilege information from the past, present, or future that could be threatening in any way, also feeds into this mismatch by getting us ready to escape or defend, even when we’re safe.

Without conscious deliberation, our first urge in many situations is to avoid what’s costly and gain what’s immediately desired, even at long-term loss or at the expense of lasting benefit. For example, we may refrain from waving another driver into a convenient parking space to avoid walking a relatively short distance ourselves, though the generosity would feel nice and the walk would be pleasant and better for our health. Or we might hold back from apologizing for an unintentional offense to avoid being vulnerable and go on with our day uninterrupted, though offering the apology would initiate reconciliation that could relieve stress and strengthen our relationship.

So what does this have to do with forgiveness and grudges? Studies of forgiveness and physical health suggest that unforgiveness (in other words, holding a grudge) may be one of these mismatches. Grudges may feel valid in the moment, but are problematic when held long-term; forgiveness feels unsteady and tender in the moment, but ultimately helps you feel better.

Why do we hold grudges?

According to forgiveness scholar Everett Worthington at Virginia Commonwealth University, forgiving means reducing negative thoughts, emotions, and behaviors toward someone who committed harm and replacing them with positive thoughts, emotions, and behaviors. Forgiveness does not mean pardoning, condoning, excusing, or justifying harm, nor does it require reconciling with the person. This is an important distinction, because believing that forgiveness does mean “getting back together” can make it feel unfair, like it invalidates our pain and suffering, which can make holding a grudge feel more sensible and appealing.

Forgiving is also not a strategy for becoming complacent when we’re being treated poorly; it does not mean rationalizing or justifying harmful conduct so that we can continue to endure it. When we forgive, we honor and remember that we felt badly in order to move forward more wisely, while letting go of ongoing, unbidden anxious and unpleasant feelings. 

Unforgiveness can also feel like a better choice because it seems easier. It is uncomplicated and unequivocal: “I am right and the person who committed harm is wrong.” This view is simple and certain, and does not require additional consideration—in other words, it carries low cognitive cost. One of the costs some people perceive of forgiveness is losing face and the possibility of applying consequences. Deciding to surrender the certainty of “an eye for an eye” logic can be challenging because it feels asymmetrical and ambiguous.

Unforgiveness can also feel protective because it motivates absolute avoidance: no further encounters or contact with those who commit harm. No more bad feelings from being reminded of the harm. Forgiveness, on the other hand, requires emotional labor—or acknowledging the hard feelings linked to a past harm and working to shift them toward a gentler, more nurturing stance. Forgiving means being open to the possibility of remembering or even encountering a harm doer again and readying ourselves to offer ease and goodwill.

Finally, studies have documented that seeing a cheater or harm doer get punished activates reward pathways in our brain, the “altruistic punishment” or “schadenfreude” signal, a motivator of the basic human preference for restoring justice. When we anticipate satisfaction as we imagine holding someone accountable or exacting revenge, it may strengthen the urge to hold a grudge.

What is left out of all these mental justifications for grudge holding, however, is the long-term detrimental impact. While feeling mad, afraid, sad, or otherwise unpleasant or upset about being harmed are healthy emotional responses in the short term, they are naturally time-bound and fluctuating. Emotions emerge in real time to guide our responses to the current context and inform our long-term knowledge, and then subside. A grudge, on the other hand, keeps these feelings pervasive and enduring. They remain intense and they recur, sometimes unexpectedly, in response to associations and reminders in our life. Lingering, recurring negative emotions overactivate the SNS, which amounts to a type of chronic stress that can increase our blood pressure, impair our immune response, increase our cardiovascular risk, and disrupt our sleep.

“Forgiveness of others is associated with risk for all-cause mortality, and the mortality risk of [forgiving someone] may be conferred by its influences on physical health,” writes Laurent Toussaint.

Two ways forgiveness is good for your health

Embracing, labelling, disclosing, and accepting difficult and unpleasant feelings about past harms enable us to be resilient. Seeking social support, to process negative feelings—which can be part of forgiving if we involve a friend, ally, supportive person, or even the perpetrator of harm if it makes sense—helps us learn, grow, and find ease and meaning from them. A recent study by Marilyn Cornish reported that forgiveness helped medical patients adapt to life changes after suffering a spinal cord injury, suggesting that accepting ambiguity as part of forgiving may benefit our response to other unforeseen circumstances.

Forgiveness improves physical health by reducing and untethering our negative emotional reactions about a prior harm or any reminders of it from our day-to-day experiences. Reducing “hard feelings” about a past harm helps restore balance between the SNS and PNS, instead of keeping us in stress overdrive.

According to a systematic review of multiple studies on forgiveness in aging and advanced illness, “Forgiveness should be taken into account among holistic care professionals as a considerable contributor to the resolution of stress associated with conflicts over the lifespan to promote well-being and health outcomes.” 

Forgiving also frees up mental and emotional resources for us to be trusting, optimistic, and self-compassionate (i.e., kind toward our own inadequacies and flaws), and promotes friendlier behaviors like participating in social gatherings, activities, and community events.

While several large-scale studies have reported that people who are more forgiving are less likely to die of any cause, and attributed the lifespan gain to the benefits of forgiveness on physical health, correlation cannot be interpreted as causal. Are forgiving people healthier, or are healthier people more forgiving?

In a recent study led by Songzhi Wu at Columbia University, participants who forgave rated stimuli that reminded them of a past harm (like a photo of an unfaithful romantic partner’s favorite restaurant) as less unpleasant. These findings suggest that forgiving someone reduces the intensity of negative emotion linked to reminders of a past harm. Another 2020 study published in BMC Psychology measured forgiveness one year, and positive emotions, social integration, depressive symptoms, anxiety symptoms, hopelessness, and loneliness five years later. Those who forgave more often fared better in all these areas, suggesting a more direct impact of forgiveness on health. A third study published in Psychology and Health revealed that people who are more forgiving of both themselves and other people sleep better:

Because forgiveness is associated with better sleep, it capitalizes on the powerful role that sleep plays in good health. If forgiveness of others and self-forgiveness can help people cope with the day’s psychological and emotional burdens in a way that frees one’s mind and promotes a more restful mental state for sleep, then they support the health-related process of sleep in meaningful ways.

When I teach the science of forgiveness, there is often a contingent of people who proudly refuse it—from a place of defiance and perceived empowerment. The rigidity, distrust, and emotional compartmentalizing that go into unforgiveness, however, amount to greater enduring cost mentally, socially, and physically than the lesser, yet significant, upfront effort that goes into deciding to forgive and emotionally shifting toward mercy and grace. Forgiving is not a gift to people for the hurt they have caused. Forgiveness is a physiologically balancing, resilience-building lifesaver for us.

 About the author; Emiliana R. Simon-Thomas, Ph.D., is the science director of the Greater Good Science Center, where she directs the GGSC’s research fellowship program and serves as a co-instructor of its Science of Happiness and Science of Happiness at Work online courses.

Keywords; forgiveness, psychology