The Prisha in siman 263 s"k 2 quotes the Beis Yosef at the end of the siman who says that candles arouse feelings of joy and this is based on the gemorah in Shabbos 25a which quotes a verse from Eichah (Lamentations) 3:17-
וַתִּזְנַ֧ח מִשָּׁל֛וֹם נַפְשִׁ֖י
-"And my soul is far removed from peace" and the gemorah says that this verse is referring to shabbos canles and the Ra"n explains that this is because the people in the house don't enjoy (suffering) being in the dark.
The Beis Yosef says that the more light there is the more Shalom Bayis and joy there will be because of the light in all the corners of the house.
(I don't know if this is allowed on this website but The Huffington post had an article about this on 02/24/2014 called "How The Light In A Room Could Affect Your Emotions").