Here is a great article explaining how our ancestor’s negative experiences affect their DNA expression, which can be inherited by future generations. For instance, if Grandma was raised in an abusive, alcoholic home or suffered some other trauma, some of that trauma and reactions to it can be passed onto future generations, predisposing them to becoming anxious or depressed.
Great info, I had been thinking about this when I wrote a few weeks back…not exactly the same but I think your topic can be talked about a lot more. http://nikkiwatson.love/2015/11/13/can-honoring-our-past-help-us-heal-our-worry-today