We’ve previously covered the use of body language analysis in international diplomacy. The Economist had an article providing more details about how it worked:

• Body language experts say that when somebody is hiding something, the way they smoke, check their watch, and even the distance they stand away from shop windows, change.
• Analysts also look for “micro-expressions” – things that last just 1/25^th of a second but reveal concealed emotions.
• Context is important. One expert notes that the body language of a suicide bomber is similar to that of somebody who may have left their stove on at home.
• The analysis can be painstaking. 30 minutes of video requires 20 hours of analysis.
• It is also expensive. The Pentagon spends $300,000 a year analyzing the body language of world leaders.
• When it works, it’s worth it. In 1979 one expert determined that Saddam Hussein’s body language indicated that he hated Iran more than Israel. Less than a year later the Iraqi leader invaded Iran.

Read other insights, how Putin’s body language has changed in recent times, and more over here.

Source: The Economist