Motivation refers to physiological or psychological factors that arouse, direct, and sustain behavior. Motivation involves states, goals, and varying intensities. Biological theories propose that instincts and drives motivate behavior for survival, competition, and altruism. Cognitive theories suggest that motivation involves reducing cognitive dissonance and achieving needs arranged in a hierarchy. Emotions theories propose that emotional stimuli lead to physiological changes and emotions, or that physiological changes lead to emotions. Basic emotions like anger, disgust, sadness, fear, happiness, and surprise are universally recognized.