My personal opinion is that it ' s rooted in sexual behavior and procreation . By nature , successful mating will culminate in pregnancy to assure continuation of the species . For the human female , this is a huge drain on self preservation . Pregnancy is lengthy and often life threatening . I ' m talking primal example here . The female needs to know if the male will remain engaged and supportive in the event of childbearing . Therefore an acceptable male partner needs to demonstrate social and personal strength as a provider of food and shelter . In other words , if you don ' t want to buy me dinner , don ' t expect me to accept your sperm . Attention this is a tongueincheek reply . And I don ' t mean eating ass . <| sep |> With enough signatures they have to respond to it 10 , 000 . With 100 , 000 signatures they will debate it in parliament .