HOW MANY SEPARATELY EVOLVED EMOTIONAL BEASTIES LIVE WITHIN US

A problem which bedevils the study of emotions, and the study of consciousness, is that we assume a shared understanding of many everyday concepts, such as ‘emotion’, ‘feeling’, ‘pleasure’, ‘pain’, ‘desire’, ‘awareness’, etc. Unfortunately, these concepts are inherently very complex, ill-defined, and used with different meanings by different people. Moreover this goes unnoticed, so that people think they understand what they are referring to even when their understanding is very unclear. Consequently there is much discussion that is inherently vague, often at cross-purposes, and with apparent disagreements that arise out of people unwittingly talking about different things. We need a framework which explains how there can be all the diverse phenomena that different people refer to when they talk about emotions and other affective states and processes. The conjecture on which this paper is based is that adult humans have a type of information-processing architecture, with components which evolved at different times, including a rich and varied collection of components whose interactions can generate all the sorts of phenomena that different researchers have labelled “emotions”. Within this framework we can provide rational reconstructions of many everyday concepts of mind. We can also allow a variety of different architectures, found in children, brain damaged adults, other animals, robots, software agents, etc., where different architectures support different classes of states and processes, and therefore different mental ontologies. Thus concepts like ‘emotion’, ‘awareness’, etc. will need to be interpreted differently when referring to different architectures. We need to limit the class of architectures under consideration, since for any class of behaviours there are indefinitely many architectures which can produce those behaviours. One important constraint is to consider architectures which might have been produced by biological evolution. This leads to the notion of a human architecture composed of many components which evolved under the influence of the other components as well as environmental needs and pressures. From this viewpoint, a mind is a kind of ecosystem1 of co-evolved sub-organisms acquiring and using different kinds of information and processing it in different ways, sometimes cooperating with one another and sometimes competing. Within this framework we can hope to study not only mechanisms underlying affective states and processes, but also other mechanisms which are often studied in isolation, e.g. vision, action mechanisms, learning mechanisms, ‘alarm’ mechanisms, etc. We can also explain why some models, and corresponding conceptions of emotion, are shallow whereas others are deeper. Shallow models may be of practical use, e.g. in entertainment and interface design. Deeper models are required if we are to understand what we are, how we can go wrong, etc. This paper is a snapshot of a long term project addressing all these issues. 1 What kinds of emotions? The study of emotions has recently become fashionable within AI and Cognitive Science. Unfortunately all sorts of different things are labelled as ‘emotions’. This is perhaps understandable among young engineers who have not been trained in philosophy or psychology. However even among specialists there many different definitions of ‘emotion’ and related concepts, such as ‘feeling’, ‘affect’, ‘motivation’, ‘mood’, etc. For instance some define emotions in terms of observable physical behaviours (such as weeping, grimacing, smiling, jumping for joy, etc.). Some define them in terms of measurable physiological changes which need 1The published version of this paper used the word ‘ecology’ here. not be easily discernible externally, though they may be sensed internally (referred to by Picard as ‘sentic modulation’). Some define them in terms of the kinds of conscious experiences involved in having them – their phenomenology. Some define them in terms of the brain mechanisms which may be activated. Even when behavioural manifestations do occur they may be to some extent culturally determined, casting doubt on behavioural criteria for emotions. For instance the sounds people make when exhibiting pain can vary according to culture: ‘ouch’ in English is replaced by ‘eina’ in Afrikaans! Some researchers regard emotions as inherently social or cultural in nature, though this may be more true of having a guilty conscience than being terrified during an earthquake. There is also disagreement over what sorts of evidence can be taken as relevant to the study of emotions. For instance, some will regard the behaviour of skilled actors when asked to show certain emotions as demonstrating connections between emotions and externally observable behaviour. Others will object that that merely reveals what happens when people are asked to act as if they had certain emotions, whereas naturally occurring emotions may be quite different. In some cases they may have no external manifestations, since people can often conceal their emotions. For some researchers, emotions, by definition, are linked to and differentiable in observable behaviour, like weeping, grimacing, jumping for joy, growing tense, etc., whereas others are more interested in semantically rich emotions for which there are no characteristic, non-verbal, behavioural expressions, e.g. ‘Being worried that your work is not appreciated by your colleagues’ vs. ‘Being worried that your political party is going to lose the next election’, or ‘Being delighted that the there is a sunny weather forecast for the day you have planned a picnic’ vs. ‘Being delighted that someone you admire very much is impressed by your research’, etc. Most of the empirical, laboratory, research on emotions has studied only simple, shallow emotions, largely ignoring semantic content, whereas most of the important human emotions (the ones that are important in our social lives, and which are the subject matter of gossip, poems, stories, plays, etc.) are deep and semantically rich. Another common difficulty is that some people use the word ‘emotion’ so loosely that it covers almost any affective state, including having a desire or motive, whereas in ordinary parlance we do not normally describe someone as being emotional just because they have goals, purposes, or preferences, or because they are enjoying a meal or finding their chair uncomfortable to sit in. If all such affective states were included as emotions, it would follow that people constantly have a large number of different emotions, since we all have multiple enduring goals, ambitions, tastes, preferences, ideals, etc. Another source of confusion concerns whether having an emotion necessarily involves being conscious of the emotion. According to some this is a defining criterion, yet that does not square with the common observation that people can sometimes be angry, jealous, infatuated, or pleased at being flattered, etc. without being aware of being so, even though it may be obvious to others. Another problem with the criterion is that it may rule out certain animals having emotions if they lack the ability to monitor and characterise their own states or lack the conceptual framework required to classify some states as emotions. Presumably a newborn infant cannot classify its own mental states using our adult categories. Does that mean that it has no emotions? Perhaps it has them but does not feel them? Perhaps an infant’s behavioural manifestations of pain, distress, discomfort, pleasure, etc. are simply part of the biologically important process of generating appropriate nurturing behaviour in parents rather than being expressions of what the infant is aware of? There is no obvious way of resolving disagreements on these issues because of the ambiguities and confusion in the key concepts used. Yet another confusion concerns whether, in order to have emotions, an organism or machine must contain an emotion-producing module of some kind, or whether some or all emotions are simply states involving interactions between a host of processes which are not intrinsically emotional, as was argued in (Wright et al., 1996). On the first view it makes sense to ask how the emotion mechanism evolved, and what biological function it has, whereas on the second view such questions make no sense. Another possibility is that the ambiguous word ‘emotion’ sometimes refers to states and processes conforming to the first view, and sometimes to the second, because our usage is inconsistent. Because of this conceptual mess, anyone can produce a program, label some component of it the ‘emotion module’ and proudly announce that they have developed a robot or software agent which has emotions. It will be hard to argue against such claims when there is no agreement on what emotions are. This is an extreme form of the phenomenon in AI of attributing mental states and human capabilities to programs on the basis of very shallow analogies, for which McDermott chided the AI community in (McDermott, 1981) many years ago, though he was concerned with the undisciplined use of labels such as ‘plan’, ‘goal’, ‘infer’.