Objects: naive physics (bibliography)
The proper domain of natural objects is the rocks and other solid objects of the natural environment. Living organisms share important characteristics with innate objects, so the objective mode of construal is useful also here. The adaptive target of this faculty relates to the potential benefits that may accrue to an organism able to anticipate the activities proper to inanimate matter--that it occupies space to the exclusion of other objects, including one's own body, that it is cohesive, bounded, does not deform, and is subject to local causes only. The categorization cues are described in the perception of objects; the primary cues turn out to be that something moves as a unit; gestalt-type cues of figural goodness are secondary. The prototypical member of the category of objects is a rock; marginal members are wind and water. The actual and culture domain of the faculty includes much of modern science, which has based itself on this mode of apprehending and construing the world. Comparative table of objective and biological modes of construal.
Artifacts form a subcategory of physical objects. The proper domain would be stone, bone, and wooden tools; the adaptive target the ability to modify objects to perform fitness-enhancing functions. In addition to the characteristics of physical objects, artifacts have a formal cause in the shape of an imposed design (while biological entities have an inherent design) that is changeable. Design in particular is subject to criteria of usefulness or functional purpose; thus, artifacts have a final cause, or telos, but this goal is attributed rather than intrinsic. The entailments of the artifact mode of construing the world is particularly important for eighteenth-century theories about a deliberately constructed 'artificial' social system. For a discussion of this topic, see for instance the discussion on Hutcheson and the Moral Engines of Community. Mechanisms are a subclass of artifacts; it is perhaps unlikely that anything resembling a mechanism formed part of the ancestral environment, so people should have a tendency to classify and understand mechanical devices in terms of biological modes of construal, until the innards of the machine are shown to consist in nothing but contact mechanics.
The causes proper to the objective domain are the material and the efficient--what we might call contact mechanics, or rigid object mechanics (for a discussion, see the perception of objects). An interesting question is whether the mind has innate inference engines for determining the causal relations in fluids; anthropological evidence suggests winds and rivers tend to be classified as animate, but htis is unlikely to be the whole story.
In force dynamics, Leonard Talmy argues that causality forms part of a larger semantic field of force dynamics, which in turn is utilized in a surprising variety of domains
Living kinds: folk biology (bibliography)
The biological mode of construal has living organisms of a certain size as its proper domain; the adaptive target is to access the potential penefits inherent in being able to utilize organisms for food and to predict their activities. It is characterized by conptual primitives such as formal causes (design) and final causes (purpose), and the explanatory notion of an invariant essence. See the table of objective and biological modes of construal for a broad comparison. Cultural applications of the biological mode range from Aristotle's physics, which maps notions of design and purpose onto inanimate matter, and Romanticism, which privileges the organic as a master paradigm.
If women tended to do more gathering and men more hunting, women should be expected to be better at locating, identifying, and remembering biological kinds, and there is some evidence this is the case: women perform better at tasks of recalling objects (Silverman and Eals 1992:533). The proper domain would of course be plants, but the actual domain appears to include the stationary environment in general, so that this skill may be seen as a spatial ability. The botanical classification systems of primitive tribes bear witness to an impressive memory capacity that may be domain specific.
The proper domain for the zoological interpretive engine is animals and their behavior, a highly significant adaptive target in the Pleistocene, and presumably with an EEA of much greater age. See the decision tree on the CogSci page for the criteria used in classifying agents; the most important is self-propulsion. There is some evidence human males have a greater ability than women to locate themselves by the help of an absolute sense of direction; this would have been useful when hunting, since it generally does not make sense to retrace one's steps. The actual and cultural domain of this faculty may include automobiles; a source I'm unable to trace right now tells of a stroke patient who had lost only his ability to name animals--but the brand names of cars were also gone, suggesting they are classified to be stored in the same neural circuitry.
Since the organisms that cause diseases are invisible to the naked eye, adaptation relating to diseases must differ radically from those relating to plants and animals. The suggestion of greatest interest is that our emotionally laden notions of purity and disgust have diseases as their proper domain. Cues for the presence of disease may include a loss of symmetry, and go some way towards accounting for a tendency to consider ugliness a disgusting characteristic. Conversely, purity is typically personified with a wonderfully smooth skin, free of parasites and pock marks. Notions of purity and contamination can then be mapped onto the social domain, as in the Indian notion of the "untouchable" caste. Racism generally may be appealing to an intuitive sense of contamination and purity, as in the "purity of the race", or the branding of a group of people as "impure". Notions of purity and impurity are also mapped onto the domain of sexuality, and more generally onto morality.
Another area in which we may be adapted to deal with germs is found in the physiological response of sleep.
Thirdly, it is possible that viruses and bacteria have co-evolved with us to further their own spreading, a phenomenon widely demonstrated among birds, reptiles, and insects. When infected, are we inclined to behave in ways which increase the chances of spreading the infection? The obvious candidate is sneezing; however, I know of no firm results in this area for humans.
Reaching even further back, disease has been put forward as an explanation for the development of sexuality. Sex is an expensive and risky mode of replication, and the benefits are not self-evident in evolutionary terms. However, the scrambling of genes would be an effective way of keeping a few steps ahead of gerrms and other parasites that otherwise would become intimately well adapted to its host.
Minds: folk psychology (bibliography)
I suspect that you wonder whether I realize how hard it is for you to be sure whether you understand whether I mean to be saying that you can recognize that I can believe you want me to explain that most of us can keep track of only about five or six orders [of intensionality]. -- Daniel Dennett (1983).
The notion of an "intentional stance" was first proposed by Daniel Dennett; Nicholas Humphrey also did early work in this field, along with Alan Leslie.
The most primitive form of inference that can be made about minds spills over into the general domain of biology: the identification of an organism as an intentional agency. See further discussion and the work of Sarah-Jayne Blakemore and Jean Decety, for instance "From the perception of action to the understanding of intention" in Nature Reviews Neuroscience 2. 561-567 (2001).
Eye direction detection
Human infants down to the age of six months show a galvanic skin reaction when they notice someone is looking at them (Baron-Cohen 1995).
Many prey animals process information about whether they have been spotted by a predator and respond by freezing or fleeing. Predators similarly process information about whether they have been spotted by the prey, and respond accordingly. Does this imply the attribution of an epistemic state, such as "X has seen me"?
The most parsimonious explanation is that no attribution of epistemic states is involved, for which a theory of mind is required. Even though no abstract self concept or formulation that "X has seen me" is likely to be involved, the information may be represented internally in several formats, as well as externally for communicational purposes. See further discussion.
[Eye researchers have found that almost all paintings that show two eyes place one horizontally centered on the canvas, perhaps as an unconscious aid to help organize the picture. Christopher W. Tyler. Painters centre one eye in portraits. Nature 392, 877-878 (1998) Scientific Correspondence. See the BBC's report (external).]
Around the age of twelve months, a human infant acquires the ability to infer that someone is looking at the same object as itself. See Baron-Cohen 1995.
A couple of months later, it will typically engage in proto-declarative pointing, or pointing at objects to direct someone's attention to it. This was first studied by Vygotsky (1962 ); see Weiskrantz 1988.
The work on mindreading is less satisfactory on the capacity to read emotions. Mark H. Davis's excellent book on empathy provides an overview of the field (Davis 1996). For evidence of a panhuman design for inferring emotions from facial expressions, see Fridlund 1994, Baron-Cohen, Riviere, et al. 1996. See also a brief overview of an adaptationist approach to emotion (Plutchik 2001) and Conceptual Adaptations 3: Social emotions for a discussion of the role of emotion in regulating cooperative behavior.
Fixed Action Patterns (FAPs) and Affective Mindreading
In "Facial expressions are contagious," Dimberg (2000) proposes human facial expressions are generated by biologically given "facial affect programs." He finds these programs can operate automatically by eliciting facial muscle reactions spontaneously and independently of any conscious process. The process does not in this case involve emotional contagion; however, there is further literature on this subject (pending topic of investigation).
The model resembles the ethological notion of Fixed Action Patterns. FAPs are reliable, stereotypic responses to cues. They are universal in a species. For an example of someone taking this tack, see Provine (1989) on contagious yawning.
Empathy: an evolved adaptation?
Davis (1996) distinguishes between perceptual, affective, and cognitive role-taking (47), and suggests the affective evolved to solve the problem of cooperation. The cognitive falls under the discussion under theory of mind below.
A functionally specialized structure for reading disgust?
Reiner Sprengelmeyer (1996) suggests that the brain may be functionally specialized for individual emotions. The April issue of Discover magazine reports that "people with Huntington's have trouble interpreting the emotions of others, mistaking fear for anger, sadness for surprise, or any of these for nothing at all. Neuropsychologist Reiner Sprengelmeyer of Ruhr University in Bochum, Germany, recently investigated this aspect of the disease by asking patients to identify the changing emotions expressed by a face on a computer screen. He found that Huntington's patients have problems recognizing all emotions except happiness, but experience the greatest difficulty of all in identifying disgust. Ten out of thirteen Huntington's patients were almost completely unable to recognize it. Sprengelmeyer believes that disgust is an emotion that arose early in our evolutionary history, perhaps as a nonverbal warning of spoiled food. And as it arose, a specific part of the brain became dedicated to its recognition. This structure, he thinks, may reside in the caudate nucleus, a part of the brain involved in cognition and movement that is always destroyed by Huntingdon's. "There is a long-standing hypothesis that all emotions are processed by the same brain structure," says Sprengelmeyer. "Our finding suggests that there are several structures that are important for decoding different emotions." (p. 22)
Theory of mind
The ability to attribute invisible mental states to others may be a uniquely human capacity, not even present in the great apes. See Povinelli, Daniel J. and Daniela K. O'Neill (2000). Do Chimpanzees Use Their Gestures to Instruct Each Other? In Understanding Other Minds.
The presence and development of a multi-stage theory of mind in human beings can be detected in a series of psychological experiments (Baron-Cohen 1995).
The attribution of simple belief states, such as "Mary believes that Tom knows where she hid the toy," is referred to as first-order belief attribution. Clark Barrett (1999) proposes this capacity first arose in predator-prey interactions. Second-order belief attribution involves modeling what person A thinks person B thinks.
Perner, Josef and Heinz Wimmer (1985). 'John Thinks that Mary Thinks That ... ' Attribution of Second-Order Beliefs by 5-10-Year-Old Children. Journal of Experimental Child Psychology 39: 437-471.
First-order false belief tasks require making inferences about someone's false belief about a matter of fact. They are typically passed by children between 3 1/2 and 4 years of age. Autistic individuals typically fail these tasks, depending on the degree of autism. ("X believes the candy is gone, even though it isn't.")
Second-order false belief tasks require making inferences about someone's false attribution of belief. These are usually passed by children around the age of 10 or 11. Again, these tasks are typically failed by autistics, though not without exceptions. ("X thinks that Y believes the candy is gone, even though the candy isn't gone.")
Faux pas represent a still more complex conceptual modeling; they are typically solved by young adults in their teens. Valerie Stone (see home page, external) has done studies with Simon Baron-Cohen on testing patients with Aspberger's syndrome on such tasks. Aspberger's patients have symptoms similar to autistics, but in a much milder form; they remain socially functional, but tend to commit gross social blunders. Autistics typically fail these tasks.
See bibliography. For a recent update, see Shallice, Tim (2001). 'Theory of mind' and the prefrontal cortex. Brain 2001 124: 247-248. Full text (theme issue, external).
Self and identity conceptions
Self and identity are complex concepts that may include several adaptations
and have a strong cultural component; for a start, see my presentation of Ulrich
forms of self-knowledge" with a preliminary sketch on the homunculus effect
and the inner self as an illusion.