The world is full of paradox. While a mother in New Hampshire pushes for defibrillators in every school to save her son and other students who might go into cardiac arrest, a mother in Ohio is accused of killing her month-old baby with microwaves, in a microwave oven. Some guard young lives with absolute ferocity, while others kill them in horrifying ways.

The mothers on the path to better protection will take care of themselves and their children. But what can be done about those who kill their children with microwaves or hammers or by throwing them off a bridge — scenarios described in recent news stories. Murder charges after the fact hardly seem sufficient. That does nothing to save the children.

Something is at work in U.S. culture that increases the possibility of filicide, the killing of a child by one of his or her parents. Compared to other developed nations, the United States has the highest rate of homicide involving children under 5, and some 60 percent of them come at the hands of the parents. Why?

What little research has been done on this topic points to character disorders and other psychiatric problems that go back to infancy. To a layman, however, there appears to be a societal problem that contributes to these horrible acts: alienation and a lack of family and community support. It takes a village to raise a child; the idiom is as valid as ever. But all that’s required to take a young life away is one sick, desperate, isolated individual.

Studies of women who have killed their children found that they were frequently victims of abuse themselves, according to an article published in the American Journal of Psychiatry in 2005. “Many had limited education, poor social support and a history of substance abuse. In addition, they were often unmarried and unemployed, and some viewed the child they killed as abnormal.”

Frequently socioeconomically disadvantaged, these women bear primary responsibility for children they can barely afford to feed and clothe, and one has to wonder which comes first — the circumstances or depression? They seem to go hand in hand. Yet the number of women in such situations is great; most have strong maternal instincts to protect their children, and very few resort to murder. What pushes those few over the edge and into the headlines?

A study released in 1969 classified the reasons that mothers kill children as altruism, psychosis, having an unwanted child, accident and revenge. Today’s thinking, though, points to more complexities.

As the journal article concludes, obviously more research to identify predictors for maternal filicide is needed to prevent these deaths. One commentary on the phenomenon bears the subtitle, “Beyond Psychosis and Into the Heart of Darkness.” It’s not enough to shake our heads at the bizarre headlines and tut-tut about deranged people. Modern science should shed light on this heart of darkness and find a way to avert these heart-breaking murders.