Stressful experiences at a young age affect the next generation, according to a new University of Haifa study. The research did show, however, that inherited adversity can be modified by appropriate intervention.

Prof. Micah Leshem of the Department of Psychology at the University of Haifa along with Prof. Jay Schulkin of Georgetown University and postgraduate students Hiba Zaidan and Neta Kvetniy-Ferdman set out to examine the cross-generational effects of early exposure to stress and enrichment. The researchers based their study on rats because of their resemblance to humans and their rapid rate of development and reproduction, which facilitates cross-generational studies.

“The similarities between rats and humans raise the question of whether similar effects might transpire in humans; for example, exposure to war or natural disasters might have heritable effects,” explains Prof. Leshem who headed the study.

The study was recently published in the journal Developmental Psychobiology.

The main findings showed that the early treatment of the mothers impacted their offspring behavior. Stress to the mothers reduced social interaction in their offspring, but improved their ability to learn to avoid distress. Male offspring were also better at coping with fear. Providing therapeutic enrichment to the offspring also offset some of the inherited effects.

According to the researchers, their study, with other evidence, “suggests that evolution equipped the parent generation to sample its environment, and then, possibly via heritable epigenetic changes, to prepare the next generation to better cope with this environment,” Prof. Leshem says. “It is important to investigate whether stressful experiences at a young age affect the next generation, and whether therapeutic experiences can minimize the trans-generational effects in humans too.

“As our study shows that the inheritance of the effects of adversity can be modified by timely intervention, this may have important educational and therapeutic implications.”