The Collaborative International Dictionary of English v.0.48:

Psychogenesis \Psy`cho*gen"e*sis\, n.
   Genesis through an internal force, as opposed to natural
   selection.
   [1913 Webster]

WordNet (r) 3.0 (2006):

psychogenesis
    n 1: the development in the life of an individual of some
         disorder that is caused by psychological rather than
         physiological factors
    2: a general term for the origin and development of almost any
       aspect of the mind