לזכות ישראל נועם שלמה בן ידיד נפשי ר' יעקב יחזקאל
Having bad middos does something to someone's brain that makes him think in a convoluted, twisted way. Thinking in a convoluted, twisted way, corrupts one's middos. So it snowballs. That is why it is critical to stop the downward spiral by fixing one's middos.
The Rambam calls his laws of middos "Hilchos Deyos". Middos and deyos [which are in the mind] are interrelated.
כשהמדות הרעות שולטות באדם דעתו מתקצרת, וקוצר הדעת עצמו מביא רוע המדות.
