Science is just beginning to explore the positive emotions and their effects on health.

However, according to Richard Davidson (professor of psychology and neuroscience at the University of Stanford) happiness is not just a vague feeling it is a physical condition in the brain that can cause.

Two brain imaging techniques – magnetic resonance imaging (MRI), and encephalogram – are invariably showed the left prefrontal cortex as the headquarters of happiness.

For example, increased activity on the left is linked to positive emotions, while at right she pointed negative thoughts of depression.

Some figures:

Those psychological tests that rank as the most successful secrete antibodies 50% higher than the average when inoculated a vaccine against influenza.

According to a Dutch study published in November 2004 and conducted for 9 years, elderly, people were optimistic two times less likely to die prematurely.

As part of a large study followed for 10 years over 1300 men, it was determined that the rate of coronary heart disease among those who said they were optimistic half were less than in the rest of the subjects.

Sources: Time, The Independent.

Read the study of Dr Karina W. Davidson february 2010 : Come ON, Get Happy. It may help your heart