These books will definitely help you understand a little bit of Dark Psychology.
“FIFTY SHADES OF GREY: When college student Anastasia Steele goes to interview young entrepreneur Christian Grey, she encounters a man who is beautiful, brilliant, and intimidating. The unworldly Ana realizes she wants this man, and Grey admits he wants her, too—but on his own terms. When the couple embarks on a daring, passionately physical affair, Ana discovers Christian’s secrets and explores her own desires.
FIFTY SHADES DARKER: Daunted by Christian’s dark secrets and singular tastes, Ana has broken off their relationship to start a new career. But desire for Christian still dominates her every waking thought. They rekindle their searing sensual affair, and while Christian wrestles with his inner demons, Ana is forced to make the most important decision of her life.
FIFTY SHADES FREED: Now, Ana and Christian have it all—love, passion, intimacy, wealth, and a world of possibilities for their future. But Ana knows that loving her Fifty Shades will not be easy, and that being together will pose challenges that neither of them would anticipate. Just when it seems that their strength together will eclipse any obstacle, misfortune, malice, and fate conspire to turn Ana’s deepest fears into reality.”