People with low self image and confidence generally become obsessive in their relationships.
Early childhood experiences also play a big role in determining how one behaves in his relationships later. Over
critical parents who constantly keep rejecting their child, scar them for life. As adults, when they get into their first relationship, they find acceptance, but eventually become possessive, if that bond is threatened in anyway.
A series of failed relationships can also lead to an obsessive personality. They grow out to be insecure individuals who fear being ditched repeatedly.
There are some obsessive lovers who turn out to be sadistic. They can even go to the extent of harming the person. Such people usually suffer from psychopathic or anti-social tendencies.
Could you please explain to me what they mean by critical parents here?
Source :
http://timesofindia.indiatimes.com/life/relationships/man-woman/Dealing-with-an-obsessive-lover/articleshow/4772399.cms