Episode number 8 of @sciencemug's podcast tells you that on Valentine's Day there's an increase in births: women are influenced by the cultural value of this day as they associate positivity and propitiousness to this festivity and appear to have a certain control on the timing of births. The Valentine's Day birth story is told in 2011 by three scientist from Yale on a paper appeared on the journal "Social Science & Medicine" [a journal cofunded by the industry of chocolate and roses but highly opposed by the lobby of Halloween and the GAPP (the Global Association of Pumpkins Producers). Listen to the podcast to understand why...]. The text and comics are here: http://goo.gl/hdzTe8 Ciaz! SM