Secrets have become harder to conceal and easier to divulge with the availability of online blogs and other social networks sites as well as open office settings. Secrets can be used as weapons. They represent power, they can generate fear.

In the shadowy world of espionage and in our ordinary lives secrets are a currency.

But why do we have secrets? And what are the consequences either for holding onto a secret or for giving it away?

(Image of a woman holding a finger to her mouth. Credit Getty Images)