Why is more to blame for Alans Actions ? Dora or Frank, and why ?

I believe that Frank and Dora are equally responsible. Dora is a devout Christian, who shared her beliefs with her son. Her husband is the exact opposite and publicly criticized his wife. None-the-less, both parents are controlling, and their confining methods of parenting made Alan feel a lack of freedom. He looked to his newfound religion as a means of achieving this fulfillment.

Society is to blame as it wants a uniformity. Society does not accept anyone that is not classified as "normal". But, what is normal?

"The normal is the good smile in a child´s eyes. It is also the dead stare in a million adults. It both sustains and kills-like a God." (Dysart)