The need for acceptance is a theme exhibited by several characters throughout Sweet Tooth. Serena, as the protagonist, is the clearest example of this theme in action. After a sheltered childhood in which her religious father rarely took the time to dote upon Serena or her sister, she feels an emotional void in her life. When she grows up and begins to take on a degree of freedom, she seeks out people who can provide her with the emotional validation which she requires. Tony, Max, and Haley are all examples of Serena striving to satisfy her need for acceptance. She depends on these older, more mature, more experienced men to guide her through life and to praise, accept, and validate her actions. She relishes the praise she receives from them because, after a childhood of being denied such validation, their acceptance carries an even greater meaning to her. The need for acceptance does not just dictate Serena’s actions, but also her romantic decisions.

Serena is not alone in her need for acceptance. Haley also exhibits an insecurity, particularly concerning his writing. When he first meets with Serena, her earnest praise of his work disarms him. He does not seek out the praise of critics or publishers, but he values Serena’s input because he has great affection for her, and she presents him with a casual sincerity which he does not find often in the pretentious literary world.