Psychology 346IC

Evolution, IQ, and Domain General Mechanisms (DGPM)

DOMAIN-GENERAL PSYCHOLOGICAL MECHANISMS (DGPM)

versus

DOMAIN-SPECIFIC PSYCHOLOGICAL MECHANISMS (DSPM)

DSPM SOLVES SPECIFIC PROBLEM OF SURVIVAL OR REPRODUCTION THAT WAS RECURRENT IN THE EEA.

DGPM DOES NOT SOLVE SPECIFIC PROBLEM OF SURVIVAL OR REPRODUCTION;

DGPM IS AIMED AT SOLVING NON-RECURRENT, COMPLEX, NOVEL PROBLEMS IN AN ADAPTIVE MANNER BY ACHIEVING EVOLVED MOTIVE DISPOSITIONS.

n
 
nHuman cognitive architecture evolved to solve recurrent problems our ancestors faced during the Pleistocene.
n“For humans, the situations our ancestors encountered as Pleistocene hunter-gatherers define the array of adaptive problems our cognitive mechanisms were designed to solve” (Cosmides & Tooby, 1994, p. 87).
nThe mind is made up of many domain-specific mechanisms= “modules.”
nHumans are designed to solve problems that range from “solicitation of assistance from one’s parents, to language acquisition, to modeling the spatial distribution of local objects, to coalition formation and cooperation, to the deduction of intentions on the basis of facial expressions, to avoiding incest…, to the interpretation of threats, to mate selection, to object recognition” (Cosmides & Tooby, 1994, p. 88).
 
nModules are “dedicated intelligences” that receive characteristic inputs and produce characteristic output.
nTheir operation is mandatory (i.e., they are automatically triggered in the presence of appropriate environmental stimulation), fast, and unconscious (but their output may be conscious). (= implicit processing
nModules have a built-in sense of relevance about what information is needed to solve an adaptive problem.
nThey are sensitive to correlated features of the evolutionary environment.
nE.g. 1: Waist-to-hip ratio is an easily perceivable cue correlated with the ability to have future offspring (Singh, 1993).
nE.g. 2: Facial recognition module.
nE.g. 3: Spatial information module—rotating figures in space, etc.
 
nOrganisms adapt to recurrent problems in the EEA (= the Environment of Evolutionary Adaptedness—the environment humans evolved in which presented the problems solved by the set of human adaptations).
n
When the environment presents recurrent problems, the optimal solution is to develop domain-specific cognitive and psychological mechanisms specialized to handle specific types of input and generate certain types of solutions.
 
n“Transient conditions that disappear after a single or a few generations may lead to some temporary change in the frequency of designs, but the associated selection pressures will disappear or reverse as often as conditions do. Therefore, it is only those conditions that recur, statistically accumulating across many generations, that lead to the construction of complex adaptations (Tooby & Cosmides, 1992, p. 69).
 
n
Modular Information processing domains: David Geary, The Origin of Mind, 2005.

Folk Psychology

n

Self

nSelf awareness: Represent self as social being and have a sense of persistence of self through time
nSelf schema: Knowledge of one’s own personality and relationships with other people
n

Individual

nNonverbal behavior: e.g., postural cues
nFacial expression
nLanguage
nTheory of Mind: Ability to infer intentions, beliefs, emotional states and future behavior of individuals; no evidence in monkeys; controversial in chimpanzees
nPerson Schema: Knowledge of specific other people and their networks
n

Group

nKin recognition: Mothers and babies recognize each other by smell;  children able to identify odor of full siblings, not half siblings or step-siblings
nIn-group/Out-group
 
 

 

nFolk Biology
nAll humans classify flora and fauna on basis of morphology, behavior, growth patterns, and ecological niche;
nDisruptions of anterior temporal cortex disrupts ability to name living but not non-living things. (Not conclusive)
nFolk Physics
nSystems sensitive to invariant features of physical space.
nFor humans, this includes ability to mentally represent physical objects and manipulate the objects, as in tool use. These may engage working memory: spatial intelligence.
nNavigation via mental maps of routes and landmarks both involve parietal cortex, but route task also involved hippocampus. Posterior hippocampus of taxi drivers in London larger than age-matched men. Volume correlated with time spent as taxi driver (Maguire et al., 2000)
 
Domain General Mechanisms and Explicit processing
nAble to define resources and develop strategies (plans) to achieve goals in rapidly changing, variable, and unpredictable environments.
 

 

Fear as an illustration of domain specific and domain general systems

 

Fear as a modular, domain specific mechanism:  Stimulus of a rapidly approaching object or a snake automatically triggers fear response. LeDoux’s Low Road mechanism: Stimulus is processed by amygdala and there is an automatic fear reaction that occurs before we are consciously aware of doing it. This is a specialized, modular, domain specific circuit. It is a cognitive reflex.

 

n
nFear as a conscious, non-modular, domain-general mechanism. LeDoux’s high road mechanism. The stimulus of the approaching object or the snake travels  to the prefrontal cortex, but it takes a much longer time to get there than the low road mechanism. When it does, we can respond in a variety of ways: Is the stimulus really potentially harmful is the noise just a car backfiring? Should I call 911? Plan some elaborate escape? Reach for my gun? These all require elaborate cognitive abilities, knowledge of the world, etc. 

 

n
nExample: Child opening a jack-in-the-box: At first, she smiles in anticipation. Then she shrinks back and shows a fear expression when the box is opened and the jack-in-the-box jumps out. This is the reflexive, modular fear response (the low road). Then she smiles when she understands that the jack-in-the-box is harmless. This is a non-reflexive, cognitive appraisal (the high road).
 

How Domain general mechanisms can evolve:

 

nProblem: How could domain general mechanisms evolve if they don’t solve any particular problem?

 

nAnswer: They could evolve if they made it easier to attain evolutionary goals like survival and reproduction.

 

nBut modules do that as well. What’s so special about domain general mechanisms?

 

nAnswer: Domain general mechanisms allow us to take in non-recurrent and rapidly changing features of the environment into account. Remember, domain-specific modules evolved because they solved problems that were recurrent over evolutionary time. Rapidly approaching objects and snakes were recurrent problems, and humans evolved modules that respond to them. So there is an automatic, modular, reflexive, low road fear response to these events. However, the domain general mechanism allows us to think about the context much more broadly (Is the object really going to hit me? Is the snake safely confined to a cage?). And we can try to think up new ways to deal with these problems beyond just reflexively respond by jumping away (Get a gun; call 911; realize there is no real problem even though we feel the fear).
Hierarchical model of motivation showing relationships between domain-specific and domain-general mechanisms.

 

Level 1 EVOLVED MOTIVE DISPOSITIONS: What people naturally want: Safety, love, sex, status
(Domain-Specific Mechanisms)

Level 2 PERSONAL STRIVINGS: Particular example of a natural want in a particular situation.

Level 3 CONCERNS, PROJECTS, TASKS
(Utilize Domain-General Mechanisms)

Level 4 SPECIFIC ACTION UNITS
(Utilize Domain-General Mechanisms)

EXAMPLE:

Evolved Motive Disposition: INTIMACY

Personal Striving: INTIMATE RELATIONSHIP WITH A PARTICULAR PERSON

Concern, Project, Task: Arrange Meeting Improve appearance Get promotion

Action Units: Find phone number Begin dieting Work on weekends


Evolution and General Intelligence

When the environment presents recurrent problems, the optimal solution is to develop domain-specific cognitive and psychological mechanisms specialized to handle specific types of input and generate certain types of solutions.

However, the human EEA contained both recurrent and non-recurrent problems. The argument is that the incredibly rapid radiation of humans resulted in recurrent situations of novelty and unpredictability.

Three hypotheses on the evolution of general intelligence

nAll hypotheses view intelligence as important for coping with novelty.
nAll hypotheses are compatible with evolutionary trend toward increased encephalization (larger brain size, especially cortex). Humans became the species with the big brain.
 

 

n
n1. The climatic variation hypothesis proposes that human intelligence was mainly beneficial in decoupling humans from dependence on any particular ecology defined by a constant climate or other invariant features. According to his hypothesis, general intelligence allowed humans to adapt to rapidly changing climates of the Pleistocene and greatly increased their range of settlement.

 

n2. The foraging hypothesis highlights the advantages to be gained from better methods for extracting resources from the environment (e.g., managed foraging), and in enlarging the range of human settlement and supporting larger populations. The foraging hypothesis is supported by data indicating that humans evolved as superpredators and manufacturers of highly complex tools by around 50,000 years ago, resulting in a wave of mass extinctions of large animals. These changes coincide not only with a larger brain but a smaller gastrointestinal tract and higher metabolism dependent on high quality food made possible by these improved foraging techniques.

 

n3. The social competition hypothesis proposes that after humans achieved ecological dominance, intelligence evolved because of it was beneficial for between-group and within-group competition among humans. This hypothesis emphasizes that cognitively, socially, and behaviorally sophisticated individuals are able to outmaneuver and manipulate other individuals to gain control of resources in the local ecology and to gain control of the behavior of other people. This hypothesis is supported by correlations between brain size and group size, especially where there are complex social relationships within groups.
 

 

Functions of General Intelligence

Discussions of general intelligence emphasize that intelligence is useful in solving novel problems. From an evolutionary perspective, a critical function is the attainment of evolutionary goals in unfamiliar and novel conditions characterized by a minimal amount of prior knowledge.
nIntelligence is about being able to solve novel problems. The more teachers have to repeat material, the less intelligence is required for understanding it.
 

Research on intelligence has consistently found that more intelligent people are better at attaining goals in unfamiliar and novel conditions characterized by a minimal amount of prior knowledge. As Carl Bereiter notes, intelligence is 'what you use when you don't know what to do' (in Jensen, 1998; p. 111). This highlights the idea that intelligence taps conscious problem solving in novel situations'situations where past recurrences would be unhelpful except perhaps by analogy or induction to the new situation.

Discussions of intelligence also emphasize conscious problem solving rather than the unconscious, automatic processing characteristic of domain-specific systems designed to solve recurrent adaptive problems.

Contrasts between general intelligence and domain-specific modules
nIntelligence (effortful problem solving) involves:
n    1, focused attention
    n2. conscious mental effort
n    3. is relatively slow compared as compared to automatic processing
n    4. deals with information input sequentially, and therefore is able to deal with only very limited amounts of information at one time,
n    5. and is unable to execute different mental operations simultaneously (sequential).
 
nDomain Specific Modules:
n    1. Don’t require attention
n    2. Unconscious, automatic processing
n    3. Are relatively fast compared as compared to effortful problem solving
n    4. deal with information input in parallel, and therefore is able to deal with a huge amount of information at one time,
n    5. are able to execute different mental operations simultaneously (parallel).

 

 
Implicit System Explicit System
o
oUnconscious Conscious
oAutomatic Controllable
oFast                                                             Relatively
oEvolved Early Evolved Late
oCommon Across   Species                                     May be unique to humans
   
oPragmatic, context-dependent Logical, abstract, de-contextualized
 
oSocial discourse Chess
oDomain specific Domain general
o
 
Parallel Processing     Sequential Processing
 
High capacity Limited by attentional and
   working memory resources.

 

Effortless                                                         Effortful
Heuristic processing                        General Intelligence
 
Acquisition by biology or                     Acquisition by culture  formal tuition
 

 

 

General intelligence is at the top of a hierarchy of cognitive mechanisms. It takes in information from a variety of different sources, combines it, and produces an output. The following figure can be thought of as showing how general intelligence takes in information from spatial, numerical, social/verbal, logic/analysis, and causal mechanisms. These five mechanisms may be thought of as Domain Specific Psychological Mechanisms, but g is domain general: It is not restricted to a narrow sort of information and it is not designed to solve a specific problem.


Information from emotional mechanisms also provide input into consciousness and influence decision making, as shown in the hierarchical model of motivation at the beginning of these notes.


IQ IS A DOMAIN-GENERAL ADAPTATION. HIGH INTELLIGENCE IS AN ADVANTAGE IN NOVEL, COMPLEX, CONSTANTLY CHANGING ENVIRONMENTS WHERE PEOPLE MUST ATTEND TO A MULTIPLICITY OF TASKS AND WHERE LEARNING NEW SKILLS HAS GREAT PAYOFFS.

PEOPLE WITH HIGH IQ ARE ABLE TO USE DSMG'S IN NOVEL WAYS TO SOLVE PROBLEMS; E.G., READING USES LANGUAGE DSMG'S IN NOVEL MANNER. HIGH-IQ PEOPLE READ BETTER, USE READING TO SOLVE ENVIRONMENTAL PROBLEMS BETTER AND ATTAIN HIGHER SOCIAL STATUS (SATISFY EMD).

SPEARMAN'S g = GENERAL INTELLIGENCE, ASSOCIATED WITH PERFORMANCE ON A WIDE RANGE OF INTELLECTUAL MEASURES VERBAL COMPREHENSION, VERBAL FLUENCY, NUMBER, SPATIAL VISUALIZATION, MEMORY, REASONING, PERCEPTUAL SPEED

VALIDITY: THE ACCURACY WITH WHICH A MEASURING INSTRUMENT ASSESSES THE ATTRIBUTE THAT IT IS DESIGNED TO MEASURE IQ IS VALIDATED WITH MEASURES OF SCHOOL PERFORMANCE 0.5 < r < 0.7
THE IMPORTANCE OF IQ: A SIBLING STUDY SIBLING STUDIES CONTROL FOR FAMILY INFLUENCES: Socio-Economic Status, PARENTING PRACTICES, NEIGHBORHOOD, ETC.

ONE SIBLING WITH IQ OF 90-110 = NORMAL
OTHER SIBLING WITH IQ > 110 = BRIGHT OR
OTHER SIBLING WITH IQ < 90 = DULL
N = 710; BOTH SEXES; AGED 28-36; PARENTS IN TOP 75% OF INCOME;

DULL NORMAL BRIGHT
INCOME IN 1993: $23,600 $33,600 $44,800
COLLEGE DEGREE: 2% 21% 56%
ILLEGITIMACY RATE
(FIRST CHILD) 45% 21% 10%
NUMBER OF CHILDREN: 1.9 1.4 1.4

BRIGHT SIB 6-1/2 TIMES MORE LIKELY TO MAKE OVER $100,000. BRIGHT SIBS WITHOUT COLLEGE DEGREE EARNED MORE THAN NORMALS WITHOUT COLLEGE DEGREE

DULL SIB 5 TIMES MORE LIKELY TO BE BELOW THE POVERTY LINE. 16.3% OF DULL SIBS BELOW POVERTY LINE; THEY TEND TO HAVE MENIAL OCCUPATIONS;

'MARKEDLY HIGHER' DIVORCE RATE THAN NORMAL OR BRIGHT;

DULL WOMEN HAD FIRST CHILD 4 YEARS EARLIER THAN NORMAL OR BRIGHT.

Click on this link to read "The General Intelligence Factor", by Linda Gottfredson: 

This article appeared in Scientific American, November 1998. It discusses the importance of IQ in the contemporary world.