It’s hard to avoid invisible wounds from the blast force of a divorce. But how gracefully parents navigate the emotional rubble afterward can determine the extent of some of their children’s injuries—particularly those to their immune systems.

According to a small study, adults who braved a bitter parental divorce as kids were three times more vulnerable to colds than those who had either happily married or amicably split parents. The study, led by psychology researchers at Carnegie Mellon University and published in PNAS, builds on research linking the prolonged stress of parental separations to immune system damage and poor health outcomes. But it adds the finer point that how parents go about a separation may be more important than the separation itself.

Researchers have long noted that children from fractured families sometimes show psychological distress, internalizing and externalizing behaviors, and educational deficits. The stressful scenarios also alter immune responses, leading to higher risks of physical ailments, such as asthma, and of being hospitalized for infectious diseases. But those associations mostly rely on observational data and take a broad view of the situation. For the new study, researchers wanted to untangle the effects of family problems surrounding separations from the separation itself.