Adventurous experiences create psychological arousal,[2] which can be interpreted as negative (e.g. fear) or positive (e.g. flow), and which can be detrimental as stated by the Yerkes-Dodson law. For some people, adventure becomes a major pursuit in and of itself. According to adventurer André Malraux, in his La Condition Humaine (1933), "If a man is not ready to risk his life, where is his dignity?".[full citation needed] Similarly, Helen Keller stated that "Life is either a daring adventure or nothing."[3]Outdoor adventurous activities are typically undertaken for the purposes of recreation or excitement: examples are adventure racing and adventure tourism. Adventurous activities can also