Volume 7 [Spring 2000]
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An Evolutionary Perspective on Consciousness
The role of emotion, Theory of Mind and self-deception
by C. Athena Aktipis
Reed College, Portland, Oregon
Why does it ‘feel like something’ to be happy or sad or angry, and why does the color yellow ‘look like something’ to us? Why do we experience indecision and emotional conflict? Why is it that we can think about our own thoughts and contemplate our very existence? What is the adaptive function of consciousness and how did it emerge in our evolutionary history?
The goal of this paper is to address the question of what consciousness is and how it came to be a part of the cognitive machinery of the human brain. I suggest that the social environment played an important role in the evolution of consciousness, leading to the emergence of the phenomenological experience (see Table 1). The modest thesis of this paper is that an evolutionary approach to consciousness that integrates emotion, Theory of Mind and self-deception might be useful in the scientific investigation of various psychological phenomena related to consciousness.
Physiological Responses and Physical Emotions
Evolutionary explanations for emotion call upon the adaptedness of certain physiological responses in specific situations (Nesse, 1990). Qualitative differences in the type of physiological arousal would have allowed more specificity in the response, further increasing the likelihood that the organism would respond to a particular situation in an adaptive way. Because these physical emotions1 were physiological responses that could cause changes in the physical appearance or behavior of an organism, possibilities arose for others to use those physiological responses to predict the behavior of that organism.
Intentionality Detection and Theory of Mind
The presence of organisms who exhibited physiological arousal in relevant circumstances led to selection pressure for the ability to predict the behavior of organisms based on their physiological responses. According to Simon Baron-Cohen (1995), this led to the emergence of Intentionality Detection, or the ability to interpret perceptual stimuli in terms of volitional states, and then the emergence of the Theory of Mind (ToM) mechanism that allowed organisms to infer epistemic mental states (pretending, thinking, knowing, believing, imagining, dreaming, guessing, and deceiving) from behavior. The selective advantage for this mechanism lies in its ability to provide more flexibility and specificity in predicting the behavior of others.
Having a notion of intentionality or a ToM mechanism was most likely a prerequisite for the evolution of social emotions, because these emotions require some understanding of the mental states of others. The humans emotions of guilt, anger, sympathy, sadness and happiness were designed to mediate social interactions (Trivers, 1971, Nesse, 1998). The social emotions can be considered physiological responses to the behavior of others that increased the likelihood of adaptive behavior those specific social situations. 2
Self-Referential Theory of Mind and the Emergence of Phenomenological Experience
In a social environment containing individuals with a ToM ability, the ability to form a notion of what another individual ‘thinks you’re thinking’ could have been quite advantageous3 . It would have provided the ability to predict the way in which others might respond to one’s behavior based upon the cues that one gives off about one’s volitional or intentional state. However, evolution would have to somehow make up for the inability to see one’s own facial expressions or observe other cues that might be easily observed by others as indicators of one’s intentions, beliefs, or perceptual state.
This could have been achieved by the emergence of an internal state associated with the external state of exhibiting physiological arousal or having certain facial expressions. I suggest that this internal state is what we experience as feeling like something to be happy or angry or ashamed. The experience of emotion, or the ability to feel, 4 may have emerged as a way to have access to the information that one is giving off about one’s intentional state and therefore, as a heuristic for predicting the reaction of others to one’s own behavior. Since it is impossible for one to actually see one’s own facial expressions, it would have been adaptive to be able to feel them. This idea is supported by the fact that the conscious experience of emotion is based on muscular feedback from one’s facial expressions5 (Izard, 1971, Tomkins, 1980, Adelmann & Zajonc, 1989).
If the experience of emotion is designed to provide information about the intentional states that others attribute to oneself, then it might have been useful to incorporate information about the state of the physical world when forming a representation of one’s motivational state (since others used such information to form a representation of one’s motivational state).6 There is an interesting study in which a female experimenter stopped men on either a precarious bridge or a safe and secure bridge and asked them to fill out a questionnaire. As predicted, men were more likely to call the female experimenter afterwards if they met her on the precarious bridge, than if they met her on the safe bridge, presumably because they were attributing their physiological arousal (from being on the precarious bridge) to the woman’s presence (Dutton & Aron, 1974).
The ability to be aware of one’s own beliefs or sensory/perceptual states probably emerged through evolutionary pressures similar to those which selected the ability to be aware of one’s intentions and emotions (i.e. physiological response). Since others had the ability to form a representation of one’s mental state, there would have been an advantage associated with ‘conscious perception,’ which would essentially be a self-referential ToM for one’s own beliefs about the state of the world. If the role of a self-referential ToM is to form a notion of what mental states (specifically beliefs about the world) others attribute to you, then having a notion of what others know you can perceive would be an important component of this self-referential ToM. For example, having the experience of consciously perceiving something towards which your eyes are pointed would give you the information that others may know you can see that particular object7 .
Self-deception and the Dissociation of Phenomenological Experience from Ultimate Intentions
With working mechanisms for forming representations of mental states that others attributed to oneself, it would also have been possible to use these mechanisms for the purpose of social manipulation and deception. It has been suggested by many that self-deception increases one’s ability to deceive others because it decreases the likelihood that one will give off cues that one is lying (Alexander, 1975, Nesse, 1992, Trivers, 1971).
If self-deception provided fitness benefits and was selected for, this probably occurred through an increasing dissociation of the mechanisms underlying conscious experience from the mechanisms underlying ultimate intentions8 . This may have enabled the brain mechanisms underlying ultimate intentions to ‘feed’ into conscious experience certain beliefs, desires and intentions. This would have led to the emergence of a ‘social interface’ that had within it a representation of a mental state that was most likely to lead the organism to fulfillment of ultimate goals without the conscious awareness of those ultimate goals9 .
Decision-Making and Indecision
In the Pleistocene, the social environment played a key role in reproductive success, so a careful evaluation of the costs and benefits that might befall others was an important aspect of deciding to perform a particular action. I suggest that indecision 10 became a part of our cognitive toolbox because it allowed us to receive input from the social environment about the potential externalities of an action (so that costs would not be imposed on those with whom one is developing relationships and benefits would accrue to those with whom one has a cooperative relationship, which would certainly exclude competitors).
The degree to which individuals were willing to impose positive or negative externalities on others probably influenced the willingness of others to enter into relationships with them (Tooby & Cosmides, 1996). Therefore, there were circumstances in which it might have been advantageous to experience indecision (even though indecision may not have been present at the level of ultimate intentions), so as to have a certain effect on one’s social environment. For example, minimizing anger in friends by ‘easing them in’ when one is about to perform a cost imposing act, being uncertain about getting involved in a romantic relationship for the purpose of eliciting certain behavior (e.g. investment) from a potential mate, or ‘keeping one’s options open’ in the case that one has to choose between two mates, could all be strategies that were made possible through the experience of indecision. 11
Applications and Predictions
If the experience of emotion evolved for the purpose of manipulating the beliefs that others have about one’s own mental state, then the subjective experience of emotion could be affected by changing the social environment. For example, this theory would predict that people experience more intense emotion when surrounded by others, particularly around those who interpret behavior in terms of proximate intentions and are less likely to ‘search for’ ultimate intentions. This approach to emotion might also be useful in determining what specific social or emotional deficits patients with frontal lobe damage exhibit.
Based on the idea that the adaptive function of conscious perception may have been to influence others to ascribe certain perceptual states to oneself, it is possible that the likelihood of conscious perception of certain cues may be based upon whether the other individual is a friend or a rival (one might be more likely to consciously perceive something that could provide benefits if the other individual was someone with whom one has a cooperative relationship).
This evolutionary approach to consciousness would predict that explicit memory (which is also considered ‘conscious’ memory) would play a larger role in influencing others, than would implicit memory (or ‘unconscious’ memory)12 , priming and the recognition of relations in a visual set (Eichenbaum, 1999). Being able to (selectively and sometimes self-deceptively) share information about facts and events could have had a significant effect on reproductive success, especially considering the importance of social relations in determining status and resource distribution in the Pleistocene13 . The functional role of explicit memory (and selective explicit memory) might be to allow for the communication of information that can most effectively manipulate others in the social environment into forming a favorable representation of ones own mental state. This framework might also have interesting applications for the study of memory in other animals. If ToM ability is, indeed, a prerequisite for the evolution of explicit memory, this means that any species without a ToM capacity could not have explicit memory.
Another area of research that might benefit from this evolutionary perspective on consciousness is the study of social manipulation and self-deception. The individual variations in self-deceptive behavior suggest that there might also be individual variations in discrepancy between one’s ultimate intentions and the experience of proximate intentions through consciousness. Individuals who are high in self-deception may have self-reflective ToMs that represent more proximate goals and individuals low in self-deception may have representations of more ultimate intentions.
Also, if the evolutionary function of indecision is to evaluate the externalities associated with potential actions and, in some cases, to aid in social exploitation, this suggests that one might be able to experimentally manipulate the degree of indecision that subjects experience. This model for indecision predicts subjects will report greater indecisiveness about performing an action that might impose costs on another individual when in the presence that individual, than when that individual is absent.
This paper presents a functional explanation for phenomenological experience based upon an evolutionary framework which neither ‘reduces’ consciousness to the physical processes (perhaps simply because we don’t have the tools to fully understand them) nor does it invoke any dualistic notions of a separation between body and mind, and it generates a variety of predictions that can be empirically tested. But does it answer the perennial question that should be asked of any theory of consciousness "Couldn’t all of this be true, and yet it still wouldn’t ‘be like anything’ to have all these properties that you ascribe to people?" That is a matter for the reader to determine. I do, however, suggest that certain evolutionary pressures may have led to the emergence of a sort of ‘social interface’ that has within it representations of the motives of oneself and others, access to certain memories 14 , perceptual information about the physical world, emotional experience, and the feeling that one is making decisions about one’s actions. The notion that consciousness evolved as a representation of the mental states that others would ascribe to oneself can be nothing more than speculative at this point, but it is intriguing that those perceptual and emotional elements that can be processed by the ToMs of others are the same elements that make up a large part of our phenomenological experience.
1 Physical emotion such as desire, fear, pain and pleasure are those which involve interaction with physical resources (Nesse, 1998). They do not necessarily involve interaction with or an understanding of the social world.
2 In the Pleistocene, the ability to interact with others and form relationships was critical to reproductive success. The importance of the social emotions in this ability is well illustrated by the case of Phineas Gage, probably the most famous individual with damage to prefrontal areas of the brain,. He had been very social and well liked, but after damage to the frontal lobes, he behaved unethically, exhibited no observance of social conventions, demonstrated an inability to plan within a com plicated social environment and had no sense of responsibility towards himself and others (Damasio, 1994).
3 This self-referential theory of mind would be a representation of the information that other’s have about one’s own intentions. It might be more appropriate to call it a theory of another’s theory of one’s own mind.
4 Damasio (1994) refers to the ‘experience’ of emotion as feeling, something distinct from the emotion itself. And there is evidence (Lane, 1998) that emotional perception can occur outside of conscious awareness.
5 This is known as the ‘facial feedback hypothesis’ (Izard, 1971, Tomkins, 1980).
6 Schacter’s (1964)two-factor theory of emotion is not very different from this notion. This theory states that the conscious experience of emotion depends on physiological arousal and the cognitive interpretation of that arousal.
7 The phenomenon of blindsight provides an example of a situation in which the brain collects sensory information without conscious awareness. Individuals afflicted with blindsight lack any perceptual visual experience, but they can still make re markably accurate guesses about the occurrence of a variety of visual phenomena, (Dennet, 1991). In a sense, blindsighted individuals have ‘beliefs’ about the state of the world, but they are not aware of their own beliefs. (A belief being a particular st ate of mind in which a certain notion about the state of the world is represented, and can presumably be acted upon.)
8 By ultimate intentions I mean the ‘purpose’ towards which one’s behaviors, feelings and beliefs are ultimately directed. Self-deception is having a belief about one’s intentions that is not accurately representative of one ultimate intentions.
9 This could be either direct (being ‘honest with yourself’), as in a feeling of hunger when the ultimate intention is the consumption of food, or indirect (engaging in self-deception) as in a feeling that one wants to be with one’s mate for one’ s entire life, when one’s ultimate (‘subconscious’) intention may be to have several offspring and then abandon that mate and the offspring to seek out a new mate.
10 By indecision I mean something qualitatively different from uncertainty. Uncertainty presumably existed before indecision, as a byproduct of the fact that it is not always possible to determine all the physical effects of a potential ac tion. I am not suggesting that uncertainty was an adaptation, however I think it is likely that indecision emerged as a tool designed to evaluate the social effects of a potential action.
11 There are probably many circumstances in which the experience of indecision has a negative, as opposed to a positive, effect on one’s social environment, but this does not suffice as an argument against the evolvability of such a mechanism. Al l that would be necessary for the evolution of mechanisms underlying indecision is an average net benefit from keeping one’s options open, or convincing others that you are averse to imposing costs on them.
12 Schacter (1987) was one of the first to make this distinction between explicit and implicit memory.
13 It is interesting to note that explicit memory retrieval (but not implicit memory retrieval) has been found to activate prefrontal regions of the brain (Schacter, 1998). Some of the same prefrontal areas have been found to be active during The ory of Mind tasks (Baron-Cohen, 1995; Fletcher, et. al. 1995; Frith, working paper; Stone, 1998), which suggests that there may be interdependence of the two processes and that it might be useful to examine the relationship between ToM and explicit memory .
14 Selective memory and ‘flase’ memories would be included in the explicit memories to which the ‘social interface’ would have access.
I would like to thank Melissa Rutherford for mentoring me and providing an intellectual environment that encouraged both creativity and critical thinking, and led to the emergence of these ideas (even the ones that she doesn’t agree with). For t heir valuable insights and feedback on earlier drafts of this paper, I thank Rob Kurzban, Melissa Rutherford, Sasha Hart and Galen Andrews. I would also like to thank Michael Aktipis, Stelios Aktipis, and Dorothy Weiss for their editorial comments.
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