In May 2012, when 'Bill' came to see me for a past-life regression, he didn't mention his life-long nail biting habit. He had various questions about how his life was going, but mainly was curious. So we did a regression session, and he saw three past lives. One as a hunter in the hunter-gatherer times, one as an unwilling sailor on a privateer (pirate ship) in about the16th Century, and the third as a German soldier on the Russian front in WW2. In all three he died violently, and felt he had little or no control over his destiny.
Today 'Bill' came back for a 'life between lives' regression, and before we started the session, he told me that since his last session he had not felt any need to bite his nails! He had no idea why this was no longer a compulsion.
During his 'LBL' session, I asked why the nail biting had stopped, and the answer came that in those past lives he had actually shown courage, even though at the time he had thought he was being passive.
So I can only assume that his sub-conscious mind received a huge ego-boost, and he no longer needs the comfort of the nail-biting.
His nails look well-groomed, and many other niggles have been smoothed out too.