Nearly 62 percent of respondents had at least one ACE and a quarter reported three or more. The remaining respondents had at least two ACEs, including 16 percent with four or more such experiences.

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When researchers first discovered a link in the late 1990s between childhood adversity and chronic health problems later in life, the real revelation was how common those experiences were across all socioeconomic groups.

But the first major study to focus on adverse childhood experiences (ACEs) was limited to a single healthcare system in San Diego. A study published Monday in JAMA Pediatrics — the largest nationally representative study to date on ACEs — confirms that these experiences are universal, yet highlights some disparities among socioeconomic groups. People with low-income and educational attainment, people of color and people who identified as gay, lesbian or bisexual had significantly higher chance of having experienced adversity in childhood.