Drawing on the literature about approach-avoidance behavior, this study tested whether asymmetries in the ways people interact with their smartphones using flick input (an input method based on swiping a key in a certain direction to produce the desired letter) influence their evaluations of the emotional valence of words. Specifically, a downward flick is regarded as an approach behavior in that the movement of a finger is directed toward the self, while an upward flick is regarded as avoidance behavior in that the movement is directed away from the self. In five studies, the predicted relationship between emotional valence and direction of finger movement on the smartphone was observed for nonwords and existing words. On average, words with more downward flick letters were rated as more positive in valence than words with more upward flick letters (hereafter referred to as the Flick effect). Of note, the Flick effect was not found among people who have never owned a smartphone, suggesting that smartphone use with flick input shapes the meaning of words.