When you have your hands behind your back, it can be interpreted in several different ways. It often is interpreted as apprehension or frustration. Some people link the gesture with anger. You really need to look for additional signals to interpret this gesture.
When shaking hands
Normally we shake hands by extending the right hand forward to meet the other person. There are special circumstances, like a surgery, that force a different approach, but the usual configuration is with the right hand forward. What we do with the left hand is optional and may provide some insight.
According to body language expert Bill Acheson, what you want to see is the non shaking hand moving forward and slightly upward as the other person approaches. That shows a positive desire to meet you, according to Bill. He describes and demonstrates the movement in the referenced video.
What you do not want to see is the other person hiding his left hand by putting it behind his back or in his pocket. That shows a negative feeling toward you.
When you are hiding a secret
When you hold one or both of your hands behind your back, it is often interpreted as having something you are trying to hide. Generally the gesture is figurative, but it could actually be literal, as in when a man hides flowers behind his back as he rings the doorbell of his girlfriend.
A gesture of openness with the hands is with the hand extended slightly forward with palms up. Keeping the hands out of sight begs the question, “what is he hiding from me.”
In the military world, when soldiers are asked to assume the “at ease” position, it means to put both hands behind their back and stand with feet apart in a comfortable stance. The connotation for some people of putting their hands behind their back is an indication of standing in a relaxed position.
Don’t know what to do with my hands
For some people, the hands behind their back is simply that they are feeling awkward at the moment and do not know what to do with their hands. You can see this movement often with shy children when they are put in the spotlight.
Defenseless and Vulnerable
Hands behind the back leaves the solar plexus, the one part of the body that is not protected by a skeletal structure,open and vulnerable. It can, therefore, be a signal of submission.
The gesture of putting hands behind one’s back can have so many different meanings that, like most body language signals, you need to consider the circumstance or look for other corroborating gestures before trying to assign a specific meaning to the gesture. Also, just as with nearly all body language, the meaning can be specific to a particular culture.
For example, when you are meeting a businessman in the Netherlands, you should avoid standing with your hands in your pocket and never leave your left hand in your pocket while shaking hands with your right (1).
Once you start looking for it, you will see examples of the hands behind back gesture in many social and business settings. Just remember that you cannot assume a precise meaning to this posture without further information. For sure something is going on, but you will need to explore a bit to determine exactly what it is.
(1) Kiss Bow or Shake Hands by Morrison, Conaway, and Borden 1994
This is a part in a series of articles on “Body Language” by Bob Whipple “The Trust Ambassador.”