In previous posts in this series I have been looking at a model of the Insular Cortex and its role in the regulation of emotions. There has been a brief summary of this model to date and then there has been a look at the James-Lange and Cannon-Bard theory of emotions. We are still no closer to exhausting all of the possibilities and so in this post I will look at some of the insights gained by Charles Darwin and disseminated in his esteemed publication ‘The Expression of the Emotions in Man and Animal’. The interested reader is directed to the Gutenberg Organisation which makes public domain texts available and which makes this particular work available in several formats.
Darwin made a close study of emotions in both animals and humans throughout his life. Indeed in his work he references many people that he had known and who had provided him with anecdotes that he describes to illustrate his points. The book is broadly divided into the following categories
(1) General Principles of Expression
(2) The Expression of Emotions in Animals
(2) The Expression of Emotions in Humans
(a) Suffering and Weeping
(b) Low Spirits, Anxiety, Grief, Dejection, Despair
(c) Joy, High Spirits, Love, Tender Feelings, Devotion
(d) Reflection, Meditation, Ill-Temper, Sulkiness, Determination
(e) Hatred and Anger
(f) Disdain, Contempt, Disgust-Guilt, Pride
(g) Surprise, Astonishment, Fear, Horror
(h) Self-Attention, Shame, Shyness, Modesty, Blushing
The categories above are something of a simplification but Darwin’s treatment of the emotions in humans is preserved. Darwin’s choice of clusters of emotions is interesting and the classification of emotions is far from straightforward. Systems of classification range from a few primary emotions through to exhaustive lists and there is considerable variation across systems. Darwin refers to the facial muscles and their role in expressing emotions. He refers back to the work of the renowned physiologists Charles Sherrington as well as the work of Dr Duchenne. Indeed the photograph above which illustrates the difference between a natural and electrically stimulated smile is taken from the work of Dr Duchenne and was included in Darwin’s publication.
As a small distraction and in relation to Dr Duchenne’s work, the reader may find the video below of interest. In this video the facial muscles of four men are stimulated in time to music. The man in the top right hand corner finds it all rather amusing and his natural smile ‘breaks through’.
Returning to Darwin’s work – he laid out three principles in relation to the expression of emotions and I will simply paraphrase him here
‘I. The principle of serviceable associated Habits.—Certain complex actions are of direct or indirect service under certain states of the mind, in order to relieve or gratify certain sensations, desires, &c.; and whenever the same state of mind is induced, however feebly, there is a tendency through the force of habit and association for the same movements to be performed, though they may not then be of the least use. Some actions ordinarily associated through habit with certain states of the mind may be partially repressed through the will, and in such cases the muscles which are least under the separate control of the will are the most liable still to act, causing movements which we recognize as expressive. In certain other cases the checking of one habitual movement requires other slight movements; and these are likewise expressive.
II. The principle of Antithesis.—Certain states of the mind lead to certain habitual actions, which are of service, as under our first principle. Now when a directly opposite state of mind is induced, there is a strong and involuntary tendency to the performance of movements of a directly opposite nature, though these are of no use; and such movements are in some cases highly expressive.
III. The principle of actions due to the constitution of the Nervous System, independently from the first of the Will, and independently to a certain extent of Habit.—When the sensorium is strongly excited, nerve-force is generated in excess, and is transmitted in certain definite directions, depending on the connection of the nerve-cells, and partly on habit: or the supply of nerve-force may, as it appears, be interrupted. Effects are thus produced which we recognize as expressive. This third principle may, for the sake of brevity, be called that of the direct action of the nervous system‘
Whilst at first glance these appear rather simple, these principles have been set out by Darwin. They occur in the context of his lifelong study of nature and his deep understanding of biology and offer us insights to be revisited.
Insular Cortex Resources on this Site
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