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Did Emotions Evolve?

Robin Reineke

"And they are more courageous, for they are full of passion and hope, and the former of these prevents them fearing, while the latter inspires them with confidence, for no one fears when angry, and hope of some advantage inspires confidence."

--Aristotle (contrasting the young and the old)

Do you feel as lost as I do after reading that? What are emotions? Where did they come from? What purpose do they serve? They enter every part of our life, whether we want them or not. Wouldn't it help us if we understood them a bit? I wanted to know why I all of a sudden feel fear, guilt, anger, or happiness so I decided to look into the topic. I had no idea how huge the topic actually is. The concept of emotion is one that is pervasive: entering numerous fields of research including psychology, biology (evolution), sociology, anthropology, and philosophy.

I started with the question, 'what are emotions'. Encyclopedia Britannica only goes so far as to say "[emotions are] a distinct feeling or quality of consciousness, such as joy or sadness, that reflects the personal significance of an emotion-arousing event," (1)(see also (2)). Any human being could have told us that emotion is a type of feeling about an event. Scientists agree that emotions are extremely important in human survival and adaptation (1). They effect how we perceive our surroundings, interpret them, and act upon these perceptions. Every field of study agrees that emotions are key to health (both physical and mental), individual development, and human relations (1). Unfortunately, this is where the agreement seems to end.

Neuroscientists study the relations between the expression of emotion and neural processes (neurophysiology), and questions such as where in the brain does emotion take place (neuroanatomy). Sociologists and anthropologists study the expression of emotion across cultures and between individuals. Philosophers discuss the interplay between emotions and values, morals, and thought. Artists, including poets, playwrights, and novelists, use emotion to portray the human experience for the enjoyment of others (1). Each school has drawn its own definitions of what emotions are and why we have them. The field that relates most closely to my question is that of Evolutionary Psychology.

The first work to be done on emotions from an evolutionary standpoint was done by our old friend Charles Darwin. His work titled, The Expressions of the Emotions in Man and Animals (3), was really the seminal work on the subject of emotions. The book, first published in 1872 was an immediate bestseller, and an immediate controversy. In it, Darwin, using accepted physiological and psychological theories, explained the reasons behind movements and expressions, and thus the emotions that are behind them. He proposed three principles to explain the "chief expressive actions" in humans and other animals. The first is what he referred to as "serviceable associated habits", ((3)). If, under a certain circumstance, an animal behaves in a way that gratifies it a desire, or takes away some sensation, it will behave in a similar way when confronted with a similar circumstance (3). A good example of this principle is in the case of a dog preparing to lie down. In the dog's natural surroundings (i.e. in brush or woodland), it would circle around the spot it intended to lie down in and maybe scratch at it a few times to push aside branches and then to remove uncomfortable stones or branches. Because this action gave the dog a more comfortable spot, and thus better sleep, the action is performed routinely before sleeping, regardless of whether the dog is in the forest or on the carpet in a home (5).

The second principle, "The Principle of Antithesis", stated that an animal, if confronted with a situation opposite the original, would perform a movement that is accordingly opposite (3). For this principle, a very interesting example was given. Darwin describes a dog and a cat in two emotional states. When affectionate, the dog's torso is down, its butt is in the air, and its tail is wagging or down. The cat, on the other hand, stands erect, with its back maybe slightly arched, its tail still and upright, and its ears pointed. The positions are opposite of those in which the animals are aggressive (3). When aggressive, the dog's body is erect, its head is held back, its hair is bristling, and its tail is stiff. The cat, accordingly, crouches low to the ground, its ears become flat against the head, and its tail whips back and forth. Thus, Darwin concluded that when the animal is trying to display affection, its position is as far from the position of aggression as possible (4).

The third principle, which Darwin titled as "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" (3), states that some motions (such as trembling under fear) are solely a physiological reaction, and have nothing to do with free will. They are involuntary nerve reactions that in some cases may have been developed, and in others are "side effects" of other physiological programs (3). Trembling with fear does the subject no good, and in fact could slow it down or render incapable of performing life-promoting tasks, thus it could not have been acquired through habit (3). Sometimes it was possible to trace the developed nerve reactions to an action acquired through habit. An example of this is the case of an infant tightly shutting its eyes when upset. "This is quite involuntary, and does not occur later in life, but the whole mechanism by which it is produced has been traced out, and it is found that it is a provision to prevent injury to the delicate vessels of the eyes by the increased flow of blood to the head during violent screaming,'' (4).

Darwin's assertions immediately provoked criticism and dispute, especially in regard to the first principle. What made the first principle so controversial was his claim that the actions acquired through habit were hereditary; ". . . some actions, which were at first performed consciously, have become through habit and association converted into reflex actions, and are now so firmly fixed and inherited. . .," (3). There grew a giant rift in the study of emotions between those taking the Nativist approach; usually supporting the genetic approach to emotion originated by Darwin, and those taking the equisitionist approach to human nature, emphasizing the importance of learning over heredity (5). The two sides of the argument have many titles, including, respectively, nature versus nurture, and biosocial versus constructivist.

The psychology side of the evolutionary psychological approach to the emotions is largely centered on the theories of several American psychologists. The first of these was William James. According to James, "Instinctive reactions and emotional expressions thus shade imperceptibly into each other. Every object that excites an instinct excites an emotion as well," (7). In other words James proposed that an a stimulus from the outside environment would create an internal physiological reaction as well as an external reaction/expression. Thus, emotion is the feeling of both the physiological and behavioral processes (1). Several years later, a Danish physician by the name of Carl Lange constricted James' original theory to state that emotion is simply the perception of physiological changes taking place internally. The two theorists were clumped together, and their ideas are referred to as the James-Lange theory. Much like Darwin's claims, the James-Lange theory faced serious criticism. Walter B. Cannon published research on animals whose internal organs were separated from the nervous system yet continued to display emotional expression (1). These three scientists theories form the basis of the psychological view of the emotions.

To date, the standard evolutionary psychological approach to the emotions is a combination of the theories of the founders of the field (discussed above) and subsequent theorists and experiments. In general evolutionary theory it is accepted that repeated encounters with similar situations were met with varying actions. Certain actions promoted life, and certain actions promoted death. Thus everything in the mind is "program" designed to solve a specific problem encountered numerous times throughout evolutionary history (6). These programs are triggered by events in the outside environment. But what if the environment triggered the 'sleep program' (i.e. the sun went down, its dark and cold) at the same time that a predator came on the scene triggering the 'run away program'? This is an example of two conflicting adaptive programs. The solution to this problem is that the mind was equipped with 'governing programs' that had the authority to override certain programs when others were activated (6). So when the environment triggered the 'run away' program, the governing programs would shut down the 'sleep program'. Not only would they shut down some programs, but these governing programs, known as superordinate programs would activate and orchestrate a multitude of programs (adrenaline levels rise, heart rate rises, hearing becomes sharper) (6).

These governing, or super ordinate programs are the emotions (6). Just like the sub-programs, they were evolved through a process of repeated encounters, with varying results that determined their success or failure. The emotions affect sub-programs by activating them, deactivating them, or adjusting their parameters so that they all coordinated in confronting the situation (6). Generally speaking, the situations where emotions play a role are those that recurred ancestrally, those that could not be dealt with without a governing program (emotions are not needed in situations where independent programs solved independent problems), and those "in which an error would have resulted in large fitness costs," (6).

A standard example of an ancestrally recurrent situation where emotion was developed as an adaptive process is being alone at night and hearing a sound. The emotion is fear: 'I am being stalked'. The super ordinate programs in the brain activate the subprograms. First, shifts in perception and attention take place: Hearing becomes more acute, motion is more detectable, and less evidence is required before acting (6). Next, priorities change: Tiredness is put aside by physiological processes, hunger is forgotten, any anxieties experienced during the day are also forgotten, and pain sensory systems are dampened. Then information-gathering programs are redirected: Finding a place to sleep or food are no longer important, so finding help or refuge become priorities. After this, conceptual frames change: things normally considered safe become labeled "dangerous", Memory is redirected: not only everything in the present situation looks suspicious but certain memories previously insignificant become clues, inference systems are activated: i.e. whatever you see, you know, learning systems are activated, physiology changes: blood is redirected, adrenalin is secreted, heart rate goes up, etc, decision-making becomes more automatic (6).

The example of fear is a good one because the scenario that our ancestors faced (being stalked by a wild animal) is similar to the scenario today of being stalked by a stranger who could be a robber, rapist or murderer. This example highlights the major beliefs of evolutionary psychologists in regard to emotions. Generally speaking, according to evolutionary psychologists, emotions are adaptive programs designed through repeated encounters that are intended to either direct other physiological programs or to directly solve adaptive problems faced by a species over time.

The interesting debates that this has generated include: do animals have emotions? How do animals express emotions? Do animals express emotions the same way that humans do? Why do humans express emotions? What are the communicative goals of facial expressions? Are some emotions maladaptive? Are all emotions adaptive? Some scientists propose that the emotions as a network are an adaptive program, but that the specific emotions themselves are simply byproducts. The aspect that I find particularly ironic and intriguing is that emotions are exactly what scientists try to avoid. Scientists are continually criticized for holding biases, for not being objective, and for becoming too emotionally attached to the studies they perform. An example of this irony is apparent in a criticism that Alfred Russell Wallace (4) made of Darwin's book, The Expression of Emotions in Man and Animals (5), "It is rather curious that an author who is not usually satisfied with anything less than a real and intelligible explanation, should yet be so ready, in some cases, to admit innate ideas or feelings", (4).

Emotions are universal. Regardless of age, gender, or culture emotions remain constant. The interplay between belief and fact, innate ideas and science, suspicion and proof, between what is inside our brains, and what is part of the outside environment exists in every aspect of humankind's experience in the world. This is an interplay that makes all science interesting, and difficult to evaluate. The study of the emotions is exiting to me for these reasons; studying them from an evolutionary standpoint attempts to merge these two opposites. Who knows if this is a good thing?

"Feelings are not supposed to be logical. Dangerous is the man who has rationalized his emotions." -David Borenstein, January 28, 2000

WWW Sources

1) Encyclopedia Britannica, The Importance of Emotions.

2) Educational Psychology Interactive: The Affective System , list of definitions for emotions

3) Charles Darwin, The Expression of Emotions in Man and Animals.

4) Alfred Russell Wallace, Review: Darwin's The Expression of Emotions in Man and Animals., A book review printed in the January 1873 number of the Quarterly Journal of Science.]

5) Theoretical Considerations on Emotion: Spinoza, Descartes, Darwin-Who Wins the Race?

6) Evolutionary Psychology and the Emotions.

7) Classics in the History of Psychology; William James, What is an Emotion (1884).

Other Interesting Links

8) Embracing the Emotions as the Path; Colours and Elements in Tantric Philosophy

9) Annual Review of Psychology; Emotion

3) Emotion Research: Cognitive and Experimental Psychology

3)3) Emotions: Observing the Fusion Between Body, Mind, and Society

3) Mental Development of the Child and Race: The Origins of Motor Attitudes and Expressions




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