The Psychobiology of Loss: Lessons from Humans and Nonhuman Primates

Although descriptions of the behavioral and medical consequences of bereavement are numerous, the biological links between grief and increased risk for medical illness are far from established. Our knowledge of some of the hormonal, physiological, and immunological consequences of stress has been advanced through the study of human populations and appropriate animal models. There is a growing consensus that there are measurable changes in a number of biological systems that have direct relevance to the increased risk for illness noted in the recently bereaved. However, studies of the process of bereavement in human populations are full of confounding design, measurement, and conceptual problems. A particularly relevant animal model with similarities to the grief process is available in young nonhuman primates, which have demonstrated a number of immunological, endocrine, and physiological responses to brief mother‐infant separation experiences. Many of these changes occur in the absence of some of the confounding factors noted in the human research. This paper reviews the results of some of the studies of biological correlates, particularly relevant to the bereavement process, in both humans and nonhuman primates, and it discusses potential social intervention strategies that may have a significant impact on the biological system and modulate the risk for illness.