While it is necessary for a spiritual director to be spiritually-minded, it also helps to be psychologically-minded. This means that without reducing everything to the spiritual, one is able to see the natural processes at works, including aspects of temperament, personality, and psychological makeup. This does not require one to understand all of psychology or even to have a degree in psychology, but to be aware of some dynamics of natural, psychological processes in human experience, thought, and behavior. While a good spiritual director will be aware of the limitations of psychology, without any knowledge of psychology there is a danger of over-spiritualizing. Grace builds on nature; it does not replace it. A spiritual director should be able to appreciate the supernatural work of grace perfecting, purifying, and elevating the natural potential of the human being. It is important to know one’s limits in psychological knowledge, but a little psychological-mindedness goes a long way.
Reference:
Acklin, T., & Hicks, B. (2017). Spiritual director: A guide for sharing the Father's love. Emmaus Road Publishing. p.131