I do agree about conditioning being, in itself, a possible source of fears.
Having said that, I'll post a link to a Spiritual Forums thread about the experience of my niece. She was psychically sensitive as a child, and as a teenager was inquisitive (in terms of related reading books). She was not raised with fears about spirits. However, she did inquire into the spirit world in a perhaps inappropriate, hazardous way.
http://www.spiritualforums.com/vb/sh...ad.php?t=50790