Earlier this summer I drove my 12-year-old daughter to a horseback riding camp near Missoula, Montana. But before she was allowed to ride, the instructor wanted to talk about how horses can help people heal from trauma. “Trauma is intergenerational,” the instructor told her. I turned the words over in my head as I stood by my vehicle, wearing a pair of my grandmother’s cowgirl boots.I thought of my grandmother as a child in Iran, nuzzling a Caspian horse in a glen several miles from her home, terrified and shaking, knowing that it wasn’t safe to return to her abusive father and the arranged marriage that awaited her.