David Pate, who used the definition of toxic stress to help him understand the hundreds of disadvantaged black men he met in his research. Credit: UWM Photo/Derek Rickert

If a soul is left in darkness, sins will be committed. The guilty one is not he who commits the sin, but he who causes the darkness. – Victor Hugo

Definitions may change how we understand – and ultimately try to improve – our world. The nascent definition of "toxic stress" did both these things for David Pate, UWM associate professor of social work.

These two words helped explain what some 500 disadvantaged black men had told him for nearly 20 years about their day-to-day wishes and challenges of being a black father in Milwaukee and elsewhere.

"A person with toxic stress is never in a place in which their stress is reduced. Day to day, they experience little comfort, little humanity," Pate said of the men he met with.

Toxic stress is defined as early exposure to chronic, unmitigated stress that affects behavior, learning and health for a lifetime. According to the New York Times, the definition may be traced to a late-1990s study on white, well-educated middle class Americans and popularized by Harvard University. In 2013, the American Academy of Pediatrics began calling on pediatricians to screen for toxic stress and urged policy makers and federal agencies to recognize and respond as well.

Meanwhile, as the definition of toxic stress took hold in the social and medical sciences, Pate – once homeless and poor himself – was working his way through those 500 face-to-face interviews. He met the men in their homes, in parks, at service providers' facilities, and he would ask each of them: What has been your experience as a black man in Milwaukee? Do you have employment concerns? Do you have concerns about your ability to be a parent?

Their answers formed a litany of despair, including:

Racism. Not enough work hours. Minimum wage jobs. Not enough money for food, medicine, clothing, rent. Poor employment readiness. Unsafe neighborhood. Chaotic home environments. A discriminatory legal system. Lack of transportation. Personal history of incarceration. Family history of incarceration. Poor education. Feeling under constant surveillance. Chronic exposure to violence. Crushing child support debt.

These individual answers, however powerful, did not paint the entire picture for Pate. Taken together, Pate said these same answers formed a remarkably clear picture of toxic stress.

"It explained the totality of these men's lives, how they faced obstacles, and their inability to maintain stability," Pate said.

Living with toxic stress injures both the brain and body. And perhaps more than any other term, it is chipping at the separation between the soft and hard sciences that study each of them.

Toxic stress is now viewed as a significant contributor to a person's risk of suicide, depression, teen pregnancy, sexually transmitted diseases, drug abuse, alcoholism, domestic violence, cancer, diabetes and organ diseases. Recent studies even show that toxic stress affects babies in utero.

Civil unrest, like that seen in Ferguson, Missouri, can be better understood as a result of living with toxic stress, Pate said.

"One of my jobs is to bring knowledge and observations—in this case about toxic stress —to students and policymakers. Government policies that work against people's well being are part of the problem, part of why people are suffering from toxic stress. Public policy has to be part of the solution to toxic stress. There is so much at stake for individuals, families and communities," he said.

But like many concepts coined by researchers (the big bang, collective unconscious, climate change), understanding and accepting how toxic stress may so deeply affect individuals can be difficult, Pate said.

"You have to be willing to understand that society is not always fair and just. The answers to society's problems are not simple and cannot be found in phrases like, 'My parents did it, so anyone can.' That does not make sense," he said.

Today, Pate considers all of his research through the lens of toxic stress and is a sought-after expert for national government agencies, including the Office of Family Assistance and the Administration for Children and Families; social service organizations, including the Center for Urban Families in Maryland; and businesses, including ICF International, a Virginia-based policy-consulting firm.

As a policy expert, Pate contributed to a U.S. Supreme Court case concerning due process and the right to legal counsel for a man incarcerated for nonpayment of child support. He is currently working under a $341,000 National Science Foundation grant (with Tonya Brito, law professor at, UW-Madison) that examines the "justice gap," or how limited access to legal assistance affects low-income litigants.

The concept of toxic stress has provided him a solid and sensible framework to use in such work.

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