I heartily recommend these books from Father Ripperger, a great priest and teacher: https://www.amazon.com/Introduction-Science-Mental-Health-Ripperger/dp/0615815391
Homily on the 4 temperaments. What are they? What are the positives & negatives of each? What saints were in these groups? How can you correct your predominant fault while knowing this?
For more please go to http://www.romans10seventeen.org & remember to say 3 Hail Marys for the priest
Further reading:
The Four Temperaments by Fr. Conrad Hock
Introduction to the Science of Mental Health by Fr. Chad A. Ripperger