Response to Jerome Kagan's Essay on Stress (2016).

To be useful, the concept of stress needs to be defined in biological terms linked to a broader framework of allostasis and its role in the adaptation of brain and body to positive and negative life experiences. A clear biological framework helps connect and organize animal and human research on stress. In particular, the concepts of "toxic stress" and "allostatic load and overload" highlight those experiences and situations that, as Kagan says, "compromise an organism's health and capacity to cope with daily challenges" (p. 442). A deeper understanding is needed of the epigenetic influences throughout the life course that contribute both to these negative outcomes and to positive ones.