New research has not shown that fears and trauma can be inherited and passed on to children. Stress alters the microRNA in blood, brain and in sperm. Research at the University of Zurich with mice, showed that the cellular process transferred fears to the nesxt generation, even when the offspring were not exposed to the stressors.
Antoher study used scents to trigger fears in mice and demonstrated that exposure to the triggering scent in mice would trigger fears in the progeny.
Psycologists have long known that behaviors can be passed from one generation to the next, but recent scientific discoveries and investigations into gene expression show that traumatic experiences leave markers on genetic code.
What is microRNA
The RNA molecules are made from the DNA using enzymes. Cells contain short RNA molecules, which are called microRNA. They regulate the functions of the cell, for instance, the copying of proteins.
When the mice in the study were exposed to stress and trauma, the microRNA behaved differently. In some cases, there were less microRNA produced in the blood, brain and sperm, and in other cases, too many. This caused a misregulation of the processes in the cell. Though the pathway causing the altering of the microRNA is not certain, researchers thought that the addition of stress hormones to the blood began the process.
http://www.nature.com/neuro/journal/v17/n5/full/nn.3695.html
http://www.sciencedaily.com/releases/2014/04/140413135953.htm
http://articles.mercola.com/sites/articles/archive/2014/08/14/hereditary-trauma.aspx?x_cid=20140827_ranart_facebookdoc