I think that a big part of development is in the environment of the child at the time they are developing. A child who is in an environment where there is a lot of noise and stress around his/her, they will not be as calm maybe as other babies who live in a calmer environment. Also, if the living areas are clean and safe for the child also make a big difference in their development as well.
I agree that the environment in which a child is raised is probably a very important factor in shaping its personality. I do think though that the largest factor in a child's early life is his or her relationship with his or her parents. It is well proven that young children need love and nurturing from their parent's from a very young age in order to develop into an emotionally functional adult. While growing up in poor socioeconomic conditions or in an otherwise less than optimal environment can have adverse results on a child's development, not receiving love and care from a parent figure is often totally devastating for a child. So while other environmental factors can of course play a role in shaping a child's development, I still think that the most important environmental factor is the presence of a loving parent.
