A remarkable case of this kind was that of a suspect of child murder. The girl told that she had given birth to the child all alone, had washed it, and then laid it on the bed beside herself. She had also observed how a corner of the coverlet had fallen on the child’s face, and thought it might interfere with the child’s breathing. But at this point she swooned, was unable to help the child, and it was choked. While sobbing and weeping as she was telling this story, she spread the fingers of her left hand and pressed it on her thigh, as perhaps she might have done, if she had first put something soft, the corner of a coverlet possibly, over the child’s nose and mouth, and then pressed on it. This action was so clearly significant that it inevitably led to the question whether she hadn’t choked the child in that way. She assented, sobbing.
Similar is another case in which a man assured us that he lived very peaceably with his neighbor and at the same time clenched his fist. The latter meant illwill toward the neighbor while the words did not.
It need not, of course, be urged that the certainty of a belief will be much endangered if too much value is sanguinely set on such and similar gestures, when their observation is not easy. There is enough to do in taking testimony, and enough to observe, to make it difficult to watch gestures too. Then there is danger (because of slight practice) of easily mistaking indifferent or habitual gestures for significant ones; of supposing oneself to have seen more than should have been seen, and of making such observations too noticeable, in which case the witness immediately controls his gestures. In short, there are difficulties, but once they are surmounted, the effort to do so is not regretted.
It is to be recommended here, also, not to begin one’s studies with murder and robbery, but with the simple cases of the daily life, where there is no danger of making far-reaching mistakes, and where observations may be made much more calmly. Gestures are especially powerful habits and almost everybody makes them, mainly _not_ indifferent ones. It is amusing to observe a man at the telephone, his free hand making the gestures for both. He clenches his fist threateningly, stretches one finger after another into the air if he is counting something, stamps his foot if he is angry, and puts his finger to his head if he does not understand--in that he behaves as he would if his interlocutor were before him. Such deep-rooted tendencies to gesture hardly ever leave us. The movements also occur when we lie; and inasmuch as a man who is lying at the same time has the idea of the truth either directly or subconsciously before him, it is conceivable that this idea exercises much greater influence on gesture than the probably transitory lie. The question, therefore, is one of intensity, for each gesture requires a powerful impulse and the more energetic is the one that succeeds in causing the gesture. According to Herbert Spencer[71] it is a general and important rule that any sensation which exceeds a definite intensity expresses itself ordinarily in activity of the body. This fact is the more important for us inasmuch as we rarely have to deal with light and with not deep-reaching and superficial sensations. In most cases the sensations in question “exceed a certain intensity,” so that we are able to perceive a bodily expression at least in the form of a gesture.