A person's psyche is formed mainly in the mother's womb.I have experienced it myself.
I was born in the pre- independence days when communal tension was at its peak. My father, only twenty at that time, was a student in Calcutta, while my young mother, pregnant with me was living in a small town in Odissa with my grand parents.Calcutta was then riot torn and one day my father was forced to go into hiding.Those days communication being very poor, he was unable to inform anybody at home.When no news came from him for a couple of days, my mother panicked and started having nightmares.And even after my father returned home unharmed she could not shake off her fright or her disturbing dreams.which continued throughout her pregnancy.
With time my mother;s feelings abated, but the harm was done. I grew up with an paralyzing fear for that community. I thought it was normal. with everybody and hence never spoke about it to anybody. But it was far from that. In my peaceful hometown, a different religion was regarded almost the same way as a different cast..
One day my mother witnessed my reaction to something connected with that religion and was highly concerned. It was then that we discussed it for the first time and I realized the reason for my inexplicable emotion. By then I was already into yoga, so I knew what to do. I worked on it diligently and managed to free myself from its grip. But there must be countless others in the world who are filled with intense hatred and anger for their fellow human beings just because their mothers unintentionally had some negative thoughts during their pregnancies, and have no means or motive to change that.
The ancient masters of India were aware of the importance of a woman's mind during her pregnancy. and also of the need to train man at every stage of life to create a safe and sane society .Hence they had formulated a code of conduct called 'Samskaras' which was then woven into religion for better acceptance and adherence.
It may not be practical to follow all the 'Samskaras' in today's world, but if the women guard their thoughts and practice yoga and meditation during their pregnancy, it will go a long way in making everybody including their own progeny healthy and happy.