More About ACEs
Adverse Childhood Experiences research didn’t start as a study of trauma. It started with an obesity clinic, a puzzling dropout rate, and one doctor who refused to stop asking why. Here’s where it came from — and why it still shapes everything we do.
Ten categories, one questionnaire
Adverse Childhood Experiences are potentially traumatic events that happen before age 18. The original research grouped them into three buckets. Your ACE score is simply how many of these ten you answered “yes” to.
Abuse
- Emotional
- Physical
- Sexual
Neglect
- Emotional
- Physical
Household Dysfunction
- Domestic violence
- Substance abuse
- Mental illness
- Jail or prison
- Divorce or separation
What each one means
The ten questions, in plain words. Each counts as one point on your ACE score if it happened before you turned 18.
Emotional abuse
A parent or other adult in your home often swore at you, insulted you, put you down or humiliated you, or acted in a way that made you afraid you’d be physically hurt. The word “often” matters: this is a pattern, not one bad day. Emotional abuse leaves no bruises and is rarely investigated, but the fear and pain it causes are just as real, and just as lasting, as physical abuse.
Physical abuse
A parent or other adult in your home often pushed, grabbed, slapped or threw things at you, or ever hit you so hard you had marks or were injured. It was the most common ACE in the original study. It often grows from the belief that hitting is an acceptable way to discipline children, yet research shows corporal punishment makes behavior worse, which can drive a spiral of harsher punishment.
Sexual abuse
An adult or someone at least five years older touched or fondled you, had you touch them sexually, or tried to or did have sex with you. It is one of the most common ACEs, and the one most often committed by someone outside the family, though almost always someone the child knows. That relationship makes the trauma confusing and shame-filled, so many survivors don’t tell anyone until adulthood.
Emotional neglect
You often felt that no one in your family loved you or thought you were important, or that your family didn’t look out for, feel close to, or support each other. It is the hardest ACE for an outsider to see, because there’s no single act to point to. But an unmet need for love is as much a trauma as an unmet need for food or shelter.
Physical neglect
You often didn’t have enough to eat, had to wear dirty clothes, had no one to protect you, or your parents were too drunk or high to look after you or take you to the doctor. The ACE Study measures this from the child’s point of view, so it includes families who simply didn’t have the money, not only parents who could provide and didn’t.
Domestic violence
You saw your mother or stepmother pushed, grabbed, slapped, kicked, hit, or threatened with a gun or knife. The original study only asked about violence against mothers, but the harm to a child is the same whoever the victim is. Watching one parent hurt another shatters a child’s sense of safety at home, and some children are hurt trying to protect the parent being abused.
Substance abuse
You lived with someone who was a problem drinker or alcoholic, or who used street drugs. A parent who is regularly intoxicated may be absent, unpredictable or aggressive, and money for food or rent may go on drugs. Addiction also raises the odds of other ACEs, including arrest, separation and foster care. Many addicted parents are themselves survivors of childhood trauma.
Mental illness
Someone in your home was depressed or mentally ill, or attempted suicide. What makes it an ACE is that the illness affected the child’s life: a condition that is well treated and managed doesn’t have to become one. Untreated, depression, anxiety, bipolar disorder and other illnesses can leave a parent unable to connect with their child or meet their emotional needs.
Jail or prison
A member of your household went to jail or prison. Seeing someone you love arrested is traumatic in itself. What follows can be worse: losing a parent from daily life, moving in with relatives or into foster care, a drop in family income, and the stigma and bullying that can come with it. A parent locked up long enough can even lose their parental rights.
Divorce or separation
Your parents were separated or divorced. For a child, it can mean a new home, a new school, less time with one parent and less money. Most children recover within a few years, and the original study’s participants grew up when divorce was rare and stigmatized, so its effect may depend on what else is happening at home. Our test also asks separately about the death of someone close.
It started in an obesity clinic, not a trauma clinic
The ACE Study grew out of a puzzling observation, not a planned research agenda — and it took over a decade to become the landmark study it is today.
The Unexpected Discovery
Dr. Vincent Felitti at Kaiser Permanente notices high dropout rates in an obesity program. Patients were losing weight — then quitting. He starts asking why.
A Surprising Pattern
Interviews with 286 dropouts reveal most had experienced childhood sexual abuse. Weight, it seemed, felt like protection. The real problem wasn’t obesity.
The Landmark Study
Felitti teams with Dr. Robert Anda at the CDC. Together they survey over 17,000 Kaiser patients — one of the largest studies of its kind in history.
Published & Changed Medicine
Results are published in the American Journal of Preventive Medicine. ACEs were far more common than expected — and strongly linked to every major cause of adult illness and death.
Want the story straight from the source? Visit the CDC-Kaiser ACE Study page →
Dr. Vincent J. Felitti
Dr. Felitti was chief of Kaiser Permanente’s Department of Preventive Medicine in San Diego when his obesity clinic’s dropout problem led him to childhood trauma almost by accident. His willingness to keep asking an uncomfortable question — why would successful weight loss make someone quit? — is the reason this research exists at all.
He went on to co-found the ACE Study with Dr. Robert Anda of the CDC, surveying over 17,000 adults and co-authoring the landmark 1998 paper that gave this field its name.
Dr. Robert F. Anda
Dr. Anda was a medical epidemiologist with the CDC when he connected with Dr. Felitti in the early 1990s, drawn by the same puzzle: why would a clinic’s most successful weight-loss patients quit right as they were winning? His training in preventive medicine and epidemiology gave the partnership something one clinic couldn’t provide alone — the tools to turn a single doctor’s observation into a rigorous, CDC-funded study of over 17,000 adults.
A high ACE score is one of the strongest predictors of poor adult health outcomes
The original Felitti/Anda study found dramatic dose-response relationships: compared to someone with an ACE score of zero, adults with a score of 4 or higher were measurably more likely to face each of the following.
Source: Felitti, Anda, et al., “Relationship of Childhood Abuse and Household Dysfunction to Many of the Leading Causes of Death in Adults” (American Journal of Preventive Medicine, 1998). Multipliers compare an ACE score of 0 to a score of 4 or higher.
ACEs and the justice system
Childhood trauma doesn’t only shape health outcomes — it can also increase contact with the justice system.
A 2021 systematic review of the existing research found that 10 separate studies linked higher ACE scores to a greater risk of justice-system contact, from juvenile arrest to adult incarceration. Read the review →
One likely path runs straight through health: as the numbers above show, unresolved trauma sharply raises the risk of alcoholism, substance use, and other struggles that can bring someone into contact with the justice system. Another path is more direct — a household member’s incarceration is itself one of the ten original ACE categories, meaning the cycle can start again in the next generation without any of those in-between steps.
Population signal, not personal prophecy
These numbers describe patterns across tens of thousands of people — they don’t describe you. The 1998 study surveyed over 17,000 adults; our own ACE test has since heard from more than 217,000 more. That scale is exactly why the findings are so statistically powerful at the population level, and exactly why they can’t tell any one individual what their life holds.
If you’ve taken our test and are wondering what your own number means for you personally, rather than for a population, that’s a different question — and we’ve written a whole page about it. Read: What Your Score Means →
“The ACE study findings suggest that the time to treat cancer, heart disease, and other chronic illness is long before they appear — by preventing and treating childhood trauma.” — Dr. Robert Anda, co-founder of the ACE Study
This is exactly why we do two things
Understanding where ACEs come from is the first step. Stopping them before they happen, and treating the trauma that’s already there, are the next ones — and they’re the whole reason Stop Abuse Campaign exists.