Fairytales are awash with psychological analysis and the folk tale of Bluebeard is no different. Set out differently in offerings by Perrault and The Brothers Grimm, the discovery is always gruesome and blood-thirsty, but can be predicted by looking at the opening descriptions which can give clues into the monster's personality and predicted behaviour patterns.
Firstly, he has deliberately allowed an 'ugly' blue beard to grow, therefore we see that his perception of himself and his looks are different to other people's - he is not conforming to the norms of society around him - even to the extent that girls are frightened of him. He stubbornly refuses to cut his beard even though it probably grows uglier, bushier,greyer and bluer by the minute. This shows his perception is altered, and he either realises it and doesn't care (bad) or doesn't realise it is off-putting just as bad.) He also deliberately gives the last wife the key to the murder scene suggesting he is looking for a justifiable reason to kill or be angry - he sets it up. This is creepy and disturbing indeed and shows that he is deranged, ill and likely to commit violent and murderous acts.