Many „pathogens“ (both chemical and behavioral) can influence how you turn out; these include substance abuse by a mother during pregnancy, maternal stress, and low birth weight. As a child grows, neglect, physical abuse, and head injury can cause problems in mental development. Once the child is grown, substance abuse and exposure to a variety of toxins can damage the brain, modifying intelligence, aggression, and decision-making abilities. The major public health movement to remove lead-based paint grew out of an understanding that even low levels of lead can cause brain damage that makes children less inteligent and, in some cases, more impulsive and aggressive. How you turn out depends on where you´ve been. So when it comes to thinking about blameworthiness, the first difficulty to consider is that people do not choose their own developmental path.It´s problematic to imagine yourself in the shoes of a criminal and conclude, „Well, I wouldn´t have done that“ – because if you weren´t exposed to in utero cocaine, lead poisoning, or physical abuse, and he was, then you and he are not directly comparable.