Sperm removal has also been posited as the driver of penis shape in humans. It has been suggested that the glans of the penis might be shaped to move previously deposited sperm away from the cervix during thrusting. Consistent with the view of the human penis as a ‘semen displacement device’, two surveys of college students showed that sexual intercourse often involved ‘deeper and more vigorous penile thrusting’ following periods of separation or in response to allegations of female infidelity.
