I found the trait he gets from Jane. In the episode "Fly", Walter is laying in bed on his back looking at the smoke detector. Then the episode goes on and he to some extent tells jessie about him being there when Jane died. This is when he really thinks about it. At the end of the episode, he is shown again in bed looking at the smoke detector. This time, however, he is laying on his side. This is due to the fact that he was going to flip her over when she threw up. This would have saved her, so he adopted it after his realization of his connection to her death.