An adventure is an activity that is perceived to involve risk, danger or exciting experiences.The term is often used to refer to activities with some potential for physical danger, such as skydiving, mountain climbing and or participating in extreme sports. The term also broadly refers to any enterprise that is potentially fraught with physical, financial or psychological risk, such as a business venture, a love affair, or other major life undertakings.Adventurous experiences create psychological and physiological arousal, which can be interpreted as negative or positive , 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?". Similarly, Helen Keller stated that "Life is either a daring adventure or nothing."Outdoor adventurous activities are typically undertaken for the purposes of recreation or excitement: examples are adventure racing and adventure tourism. Adventurous activities can also lead to gains in knowledge, such as those undertaken by explorers and pioneers. Adventure education intentionally uses challenging experiences for learning.