You'll probably want to copy and paste this one for your spouse....

A new study from Princeton University finds a link between sex and brain power. For the study, researchers had two groups of rats, one group was only allowed to have sex once every two weeks and the other group had sex daily. At the end of the study, scientists found that rats that had more sex experienced more nerve cell growth and had lower levels of stress hormones. In humans, nerve cell growth is associated with well-being and mental alertness. In fact, other studies have linked sex and exercise to growth in the hippocampus, the part of the brain responsible for memory and learning. Additionally, previous studies have have shown sex brings more oxygen and fresh blood to the brain. (Daily Mail)