I want to say something, but I cannot find the words. I get the feeling that I must make a gesture. Then, suddenly as it seems, I know what I mean. The thought pops up. Many of us have had this experience, maybe you too: A gesture stimulates your thinking.
We make gestures for many reasons. I want to draw your attention to something, so I point to it. I want to call a waiter, so I raise my hand. A gesture can be a greeting. I want to show you how a thing looks like and I indicate its shape with my hands. Some gestures have even clear, predetermined meanings. As these examples show, we make gestures or wave our hands with the purpose of communication. But not everybody makes the same gestures in the same situations. Gestures cannot only be different from person to person but also from culture to culture. When a Greek makes the gesture meaning “come here”, a Dutchman will think that the person wants to express that you must go away. People also adapt their gestures to the audience.
Communication is not the only function of gestures. We make them also when talking on the telephone. Blind people make also gestures and the non-blind do when talking with a blind person. One of the non-communicative functions is that they help us learn. It’s obvious that we cannot learn how to drive a car by simply reading a book “how to drive a car”: we have to practice it in order to be able to do it. But in education there is a method called “total physical response” that is based on the idea that you learn a language better by doing what you say. For instance, when you want to learn what the Latin sentence “aperite fenestram” means, it helps that you actually opens a window, since fenestra=window and aperite=open! In other words, doing what you say helps your memory.
But did you know that gestures also help you think? For example – and now I quote from source 1) below – “consider a math problem like 3+2 +8 =___+8. A student might make a ‘v’ shape under the 2 and 3 with their pointer finger and middle finger, as they try to understand the concept of ‘grouping’ – adding adjacent numbers together, a technique that can be used to solve the problem. ... Students who are coached to make the ‘v’ gesture when solving a math problem like 3+2+8 = ___+8 learn how to solve the problem better [than those who aren’t].” This is a simple case of how gesturing helps you think, but generally it is so that gesturing helps to think “in any situation where the person who is speaking and gesturing is also trying to understand – be it remembering details of a past event, or figuring out how to put together an Ikea shelf.” (ibid.) Generally it’s so that waving your hand helps you think, whatever it is about. It’s a new challenge of the idea that body and mind are different substances, so the old idea of Cartesian dualism. Cognitive psychologists call this challenge “embodied cognition”, which “views concepts as bodily representations with bases in perception, action and emotion” (ibid.).
In the Netherlands and many other countries it is so that the accused in a trial is free to move in the sense that he doesn’t have handcuffs and the like that can limit his gestures. This is obvious for, as long as the judgement hasn’t yet been pronounced, he is still legally innocent. In other countries, however, the accused cannot make the gestures and waves he likes, because his hands have been tied. This a psychological disadvantage, because it is humiliating and it makes that other people (including the judges or jury) tend to look down on the accused – consciously or unconsciously –, which may impede a fair trial (in the end the accused may be innocent). Now we see, however, that being chained is also detrimental for the accused in another way. For the simple fact that his hands are chained makes that the accused cannot freely think in the way he would if his hands were free. In other words, in handcuffs (or with his hands tied in another way) the accused cannot freely defend himself. Seen that way, being cuffed in a trial is a violation of human rights. Thoughts are free, but you must be able to have them.
2) https://www.quickanddirtytips.com/education/grammar/gestures-are-handy-for-speaking-and-thinking?page=2or just google “gesture and thinking”.