It’s a natural instinct.
When your horse gets nervous and starts “antsing” around, you try and calm him by looking down at him, petting him on the neck and loosening the reins. A loving look, a pat on the neck and a release of the reins are three responses that would seem to take the pressure off of him, right?
Not so much … actually those actions are often the opposite of what you need to do.
Granted the touch of a hand on the neck for some horses could be comforting, but to others it might signal a reward for the movement.
Secondly, regarding the release of the reins … well … a horse learns by the release of pressure so upon closer inspection, if this is true, then loosening the reins (releasing pressure) would reinforce his nervous behavior.
A more high strung, or fidgety horse (for any reason) quiets down with consistent guidance and a redirection of his focus. Those actions calm him. If you just react and release the reins, then you have not guided or redirected him.
Sometimes it helps to redirect his focus and guide him into some “work”… like walking or trotting in a circle … or backing up … or something he knows and you can repeat. Once he is “working” and you feel a softening in his once tight muscles and staccato movements, THEN you can loosen the reins to reward his softening/calming. If he gets tight again, then redirect, focus and do the work routine again until he gets soft and relaxed … and then release again. Repeat a million (-: times as necessary … or however many times it takes to focus and work until relaxed and released.
So release for calmness. Guide, focus and work for random motion.
Don’t forget to check in on your own emotions, too. Your horse is a powerful reflector of your emotions. In most cases, when you are in a heightened energy state, so is your horse. When you let down and relax, so does your horse.
Keep your eyes up, too. Eyes up evoke the positive emotions within you of focus and steadiness. Eyes down evoke a wide range of undesirable emotions.