Evolutionary history and personal history combine to determine motivation. Psychological mechanisms evolved to solve problems of survival and to satisfy basic needs. Sexual selection is the basis for women preferring men who signal that they are good providers and dependable. Men prefer youth and beauty as signals of a woman's fertility. After achieving financial security, women prefer men with nice traits. Jealousy evolved to protect a relationship. An evolutionary mismatch occurs when environmental offerings interfere with evolved behavioral tendencies like excessive smartphone use degrading face-to-face interactions. Evolution influenced our preference for sweets and fats; these foods indicated high calories in a time of scarcity. Humans evolved to fear snakes, spiders, and lizards, since these creatures were dangerous in our evolutionary past. The unanswered question is why humans the world over enjoy music.