As long as trading is concerned, nothing beats emotions, because your thinking capacity can be right, but if you are unable to control your emotions like fear or greed, all your trading skills will be laid waste, because lack of emotional control makes you take stupid decision you wouldn't ever take even when you are quite sure of what the market is about doing.
Lack of emotional control is what makes you questions the analysis you made which was actually right, you will see yourself cutting your losses in a trade that if you had stayed more longer you would have won and make a fortune from.

Then as for the psychological aspect, if it's not right, you practically wouldn't be able to make the right decisions and the psychology of a trader mostly get bruise when he or she has gotten some back to back and back to back losses, anytime a trader is  experiencing such, the best he can do for himself and regain his sanity is to stay off the market till he or she has cleared his head, but my  overall verdict is that they are both influencial on a trader.