Additionally, under the umbrella of evolution, is Darwin's term sexual selection. This refers to how the female selects the male for reproduction. The male is motivated to attain sex because of all the aforementioned reasons, but how he attains it can vary based on his qualities. For some females, they are motivated by the will to survive mostly, and will prefer a mate that can physically defend her, or financially provide for her (among humans). Some females are more attracted to charm, as it is an indicator of being a good loyal lover that will in turn make for a dependable child-rearing partner. Altogether, sex is a hedonistic pleasure-seeking behavior that satiates physical and psychological needs and is instinctively guided by principles of evolution.