Women who use birth control as a method of contraception prefer less masculine men. According to experts, gentle features in men are an indicator of fidelity and stability. For partners who are meeting for the first time, and at that time the woman is on birth control, she chooses a man with less masculine traits. Women between the ages of 18-24 take part in a study. The researchers tracked their strong gender preferences by showing them pictures of different faces with more masculine and less masculine features. The pictures were shown to the volunteers twice. The first time is during a period in which they are not on birth control, and the second time is after three months of taking the pills. The results showed that when taking birth control, women chose the pictures of men with gentler features. The study data is published in the journal Psychoneuroendocrinology. Modern oral contraceptives contain hormones similar to those synthesized in the body. The main purpose of birth control pills is to prevent unwanted pregnancy.