One of the most well-known scientists studying love is biological anthropologist, author, and TED Talk guru Helen Fisher. Fisher is interested in how the brain’s chemistry shapes romance, and among her many interesting findings is the discovery that love and the limbic reward system are closely linked. This means that you can feel genuinely high when falling in love. While love can feel great, inviting someone new into your life also requires vulnerability. Feeling vulnerable can be a little scary, so it can trigger our adrenal glands to release cortisol (aka the stress hormone) in an effort to combat the fear. One theory is that this dump of cortisol constricts the blood vessels in our stomachs, leading to a decreased appetite. An abundance of cortisol can also cause insomnia
