The reason for female jealousy can be found in the first-aid kit, according to Dutch scientists, quoted by The Daily Mail. Modern oral contraceptives contain hormones similar to those synthesized in the body. The main purpose of birth control pills is to prevent unwanted pregnancy. Research conducted to establish the effect of hormones in oral contraceptive pills shows that they make women much more suspicious and therefore contribute to doubting the fidelity of their partners more often. Dutch psychologists from the University of Stirling studied 275 women who answered questions to assess the degree of trust in their partner next to themselves. The participants in the research on the assignment of the scientists also evaluate their attractiveness. They are also asked to share how they feel when their partner talks or flirts with another woman, and whether they worry that they might be left for another. The women in the study were between the ages of 17 and 35 and had been taking different types of oral contraceptives for at least three months. The results of the study show that the higher the dose of estrogen in contraceptives, the stronger the feeling of jealousy in women. Scientists are of the opinion that when choosing a method to prevent pregnancy, the way in which the tablets will affect their emotions should also be taken into account. The authors of the study suggest that among the side effects of oral contraception are a decrease in sociability, a change in priority when choosing a partner. Another study conducted by British scientists shows that women who take birth control pills have a harder time choosing a genetically suitable partner. Oral contraceptives induce in the woman’s body a state of false pregnancy with all the side effects – feeling of nausea, headache, tension in the chest, abdominal pain. In addition to these side effects typical of anti-baby pills, scientists have found that contraceptives alter women’s innate ability to choose a genetically suitable partner based on his smell. This ability is related to the genes of the immune system that ensure the birth of healthy children, and in most cases it is subconscious. The results of the conducted scientific experiments show that the participants taking oral contraceptives are much more likely to choose representatives of the opposite sex whose smell is similar to their own. Researchers remind us that we are subconsciously attracted to people who smell different from us. According to the authors of the study, the effect that contraceptives have on perceptions can not only affect the ability to reproduce, but also lead to the breakdown of the relationship.