A 1989 study indicated that an individual's impression of boredom may be influenced by the individual's degree of attention, as a higher acoustic level of distraction from the environment correlated with higher reportings of boredom. Boredom has been studied as being related to drug abuse among teens. Boredom has been proposed as a cause of pathological gambling behavior. A study found results consistent with the hypothesis that pathological gamblers seek stimulation to avoid states of boredom and depression. It has been suggested that boredom has an evolutionary basis that encourages humans to seek out new challenges. It may influence human learning and ingenuity.