Psychology 346IC

EVOLUTIONARY PSYCHOLOGY

LEDA COSMIDES AND JOHN TOOBY

INTERESTED IN 'NATURAL COMPETENCIES'; i.e., ABILITIES TO SEE, SPEAK, FIND SOMEONE BEAUTIFUL, FEAR DISEASE, FALL IN LOVE, RECIPROCATE A FAVOR, EXPERIENCE MORAL OUTRAGE

l    These abilities are universals—aspects of normative development.

    All people have these abilities.

l    Not interested in individual differences—why one child is nicer or more aggressive than another
 

THESE ACTITIVIES ARE SUPPORTED BY A HETEROGENEOUS ARRAY OF COMPLEX COMPUTATIONAL MACHINERY; i.e., A SET OF MENTAL ADAPTATIONS THAT EVOLVED TO SOLVE PARTICULAR ADAPTIVE PROBLEMS IN THE HUMAN ENVIRONMENT OF EVOLUTIONARY ADAPTEDNESS (EEA).

EEA = ENVIRONMENT OF EVOLUTIONARY ADAPTEDNESS =
ENVIRONMENT WHICH HUMANS EVOLVED IN AND WHICH PRESENTED THE SET OF PROBLEMS THAT WERE SOLVED BY THE SET OF HUMAN ADAPTATIONS.

EXAMPLE: ATTACHMENT IS AN ADAPTATION THAT SOLVED THE PROBLEM PRESENTED BY AN ANCESTRAL ENVIRONMENT WITH PREDATORS AND OTHER DANGERS TO INFANTS. THIS ANCESTRAL ENVIRONMENT IS THE HUMAN EEA.

Three levels:
ADAPTIVE PROBLEM

COGNITIVE PROGRAM

NEUROPHYSIOLOGICAL BASIS

EVOLUTIONARY PSYCHOLOGY'S RESEARCH PROGRAM: INFERENCES CAN BE MADE FROM ONE LEVEL TO ANOTHER. e.g., THEORIES OF ADAPTIVE PROBLEMS GUIDE SEARCH FOR COGNITIVE PROGRAMS AND ULTIMATELY FOR A NEUROPHYSIOLOGICAL BASIS.

THE STALKING HORSE: THE STANDARD SOCIAL SCIENCE MODEL (SSSM)
SSSM: MIND IS BLANK SLATE: THE ONLY EVOLVED STRUCTURES ARE GENERAL PURPOSE LEARNING DEVICES;

Cosmides and Tooby attack an extreme position -- the position that there are no specialized systems in the human mind. They term this the Standard Social Science Model. Still, there are probably more than a few psychologists who accept the SSSM.

THE CONTENT OF THE HUMAN MIND IS NOT PRE-DETERMINED OR INFLUENCED BY OUR EVOLUTIONARY PAST

IN PSYCHOLOGY: LOCKE AND HUME, WATSON AND SKINNER, TO MODERN SOCIAL LEARNING THEORY (BANDURA)

IN ANTHROPOLOGY: 'CULTURAL DETERMINISM' -- THE BOASIAN SCHOOL

The SSSM proposes that the same mechanism is responsible for:
LEARNING LANGUAGE
RECOGNIZING EMOTIONS
NEGOTIATING FRIENDSHIPS
FALLING IN LOVE
DEALING WITH CHILDREN

lEP fundamentally rejects this premise:
lDifferent mechanisms are responsible for different tasks.

The Swiss Army Knife Analogy: Different tools for different tasks: Different psychological mechanisms for different tasks.

EP says the mind is like a Swiss Army knife; SSSM proposes mind is like a simple penknife.


FIVE PRINCIPLES OF EVOLUTIONARY PSYCHOLOGY

(1) THE BRAIN IS A PHYSICAL SYSTEM. IT FUNCTIONS AS A COMPUTER DESIGNED TO GENERATE BEHAVIOR APPROPRIATE TO YOUR ENVIRONMENTAL CIRCUMSTANCES

(2) OUR NEURAL CIRCUITS WERE DESIGNED BY NS TO SOLVE PROBLEMS THAT OUR ANCESTORS FACED DURING HUMAN EVOLUTIONARY HISTORY.

EXAMPLE: HUMANS AND DUNG FLIES RESPOND DIFFERENTLY TO FECES.

MORAL: ENVIRONMENTS DO NOT SPECIFY APPROPRIATE BEHAVIOR; BRAIN VIA NS DOES.

BRAIN IS NATURALLY CONSTRUCTED COMPUTATIONAL SYSTEM WHOSE FUNCTION IS TO SOLVE ADAPTIVE INFORMATION PROCESSING PROBLEMS.

ADAPTIVE PROBLEMS ARE
(a) RECURRENT IN OUR EVOLUTIONARY PAST;

Natural selection can only work on problems that occur repeatedly over very long periods of time.

(b) THEIR SOLUTION INCREASED FITNESS IN THE EEA.

(3) WE ACCOMPLISH DIFFICULT TASKS EASILY AND UNCONSCIOUSLY. THE CIRCUITRY IS COMPLEX, BUT WE ARE NOT CONSCIOUS OF IT.

CONSCIOUSNESS IS LIKE BEING PRESIDENT: YOU ARE AWARE OF HIGH LEVEL CONCLUSIONS PASSED ON BY THOUSANDS OF LOWER LEVEL MECHANISMS.

EXAMPLE: VISION: CELLS SPECIALIZED TO DETECT MOTION, VERTICAL SURFACES, HORIZONTAL SURFACES; CIRCUITS SPECIALIZED FOR JUDGING DISTANCE, DIRECTION OF MOTION.

(4) DIFFERENT NEURAL CIRCUITS ARE SPECIALIZED FOR SOLVING DIFFERENT ADAPTIVE PROBLEMS.

VISION, HEARING, LOVE, MORAL OUTRAGE HAVE SEPARATE CIRCUITS. THE BRAIN IS A SET OF MINI-COMPUTERS (MODULES) DESIGNED TO SOLVE SPECIFIC PROBLEMS. THESE MODULES ARE FUNCTIONALLY INTEGRATED TO PRODUCE BEHAVIOR.

EXAMPLE: INFANTS AT 2-1/2 MONTHS HAVE 'PRIVILEGED HYPOTHESES': i.e., THEY ASSUME WORLD IS MADE UP OF RIGID OBJECTS CONTINUOUS IN SPACE AND TIME; THEY ARE SURPRISED IF ONE OBJECT APPEARS TO GO THROUGH ANOTHER, ETC.

THE BRAIN CONSISTS OF DOMAIN-SPECIFIC CIRCUITS FOR LEARNING AND REASONING. The circuits are

(a) ARE DOMAIN SPECIFIC: EACH MECHANISM IS SPECIALIZED FOR A PARTICULAR DOMAIN (Vision, Love, Sexual attraction, Emotion recognition, etc.)

(b) SOLVE SPECIFIC ADAPTIVE PROBLEMS;

(c) DEVELOP IN ALL NORMAL HUMANS (UNIVERSALS);

(d) DEVELOP WITHOUT CONSCIOUS EFFORT OR FORMAL INSTRUCTION;

(e) APPLIED WITHOUT CONSCIOUS AWARENESS OF UNDERLYING LOGIC;

Example:

lThe Wason Selection task.
lProblem: How do you falsify a logical rule such as “if p, then q”?
l

The only way to falsify it is to find examples of p and not-q.

Wason Selection Task.
Subject sees these cards.
A K 8 5
p -p q -q
 
Which card would you turn over to falsify the rule “if a card has a vowel on its letter side, then it has an even number on its number side”?
Ans: The A card (rule is falsified if an odd number on the  other side) and the 5 card (rule is falsified if there is a vowel on the other side).
This problem is difficult for university students; ~90% get it wrong. Most choose A (which is okay) and 8 (not okay).
 

Casting it as a social problem of costs and benefits leads to much higher correct responses.

Rule: If you receive a benefit, then you must pay the cost.
   b        -b       c          -c
benefit    no-benefit pay-the-cost didn’t-pay the cost
 
Falsified by looking under benefit (b) to see if you paid the cost, and by looking under the “didn’t pay the cost” card (-c) to see if it says “receives the benefit.
This problem is much easier.
Hypothesis: People are much more logical when dealing with social problems that occurred repeatedly over evolutionary time.
Confirmation:
 
1. Some cross-cultural evidence;
 
2. Brain damaged subject who was poor at solving cost-benefit  rules but good at solving precaution conditionals: If you engage in hazardous activity, then you must take precaution. This suggests domain-specificity: We have different brain mechanisms for solving social conditionals and precaution conditionals.
 

 

l(5) OUR MODERN SKULLS HOUSE A STONE-AGE MIND.
lWE LIVED AS HUNTER-GATHERERS FOR 99.9% OF OUR 10 MILLION YEAR EVOLUTIONARY HISTORY. OUR ADAPTATIONS ARE DESIGNED TO SOLVE THE PROBLEMS OF HUNTERS AND GATHERERS.
lOUR ADAPTATIONS DO NOT NECESSARILY GENERATE ADAPTIVE BEHAVIOR NOW.
lOUR ADAPTATIONS MAY NOT PRODUCE FIT BEHAVIOR IN CONTEMPORARY ENVIRONMENTS.
lMismatch Theory
lEXAMPLES: PEOPLE LOVE TO EAT SWEET, SALT, AND FAT; BUT IN MODERN ENVIRONMENT OF FOOD SURPLUSES AND REFINED SUGAR, THIS MAY LEAD TO HEALTH PROBLEMS.

Evolutionary Psychology and Learning

EP: THE BRAIN DOES NOT POSSESS CONTENT-FREE LEARNING DEVICES AS PROPOSED BY BEHAVIORISTS AND SOCIAL LEARNING THEORISTS.

PREPARED LEARNING: WE EASILY LEARN TO FEAR SNAKES, BUT NOT GUNS OR ELECTRIC SOCKETS. RATS EASILY LEARN TO AVOID POISONED FOOD BUT HAVE GREAT DIFFICULTY ASSOCIATING ILLNESS WITH LIGHTS OR SOUNDS.

WE SHOULD ASK: 'WHICH INSTINCTS CAUSED THE LEARNING?', NOT WHETHER THE BEHAVIOR IS THE RESULT OF LEARNING OR INSTINCT.

(BUT HOW CAN C & T EXPLAIN THAT WE CAN IN FACT LEARN TO FEAR GUNS AND ELECTRIC OUTLETS, FIX TV SETS, IMITATE NOVEL BEHAVIORS, AND RATHER EASILY AT THAT?)

Evolutionary Psychology: The Bottom Line
•The mind is composed of a large number of mental modules each designed to solve a specific problem.
•For example, there is one mechanism for perceiving three dimensions, another for anger, another for falling in love.

 

•The mind is like a Swiss Army knife; i.e., it has lots of specialized tools.
•

There is no such thing as general intelligence, general learning, or any other general ability to solve problems.