- Evolutionary psychology is interested for the most part in those things people have in common, not their differences.
- We are interested in adaptations: mechanisms that evolved to solve problems for our ancestors in the EEA.
- Those mechanisms are basically the same from one person to another because people who did not have them left few offspring.
- All humans have four-chambered hearts because variations from that design did not work as well in humans, if indeed they worked at all
- People differ on many dimensions, of course: height and weight, eye and hair colour, and so fourth
- Some of the dimensions that we vary on are behavioural: musical ability, friendliness, and the like.
- Behavioural genetics focuses on the genetic basis of differences between people, whereas evolutionary psychology focuses on the
(presumably genetic) mechanisms that are common to all people.
Why is There Individual Variability in Behaviour?
Normal Variation Around an Optimum
- It is likely that, just as for height, much variability in human intelligence and personality is simply a byproduct of sexual reproduction.
The Optimum Value of a Trait May Vary Over Time.
- The optimum value of some traits can vary from time to time.
- One year may be dry with little food to eat; the next year may have plenty of food.
- If conditions vary, selection will not drive the trait to a narrow range of expression.
- Spatial variation in food supply or predator density would similarly maintain variation in vigilance.
- It is important to note that the variation in the environment must be slow relative to the lifetime of the individual for selection to
maintain genetic variants in the population.
- It is possible that frequency-dependent selection helps to maintain the psychological variation in the population.
Many Psychological Traits Are Facultative.
- We have seen many times throughout this book that psychological mechanisms are highly responsive to the environment.
- The optimal value of various personality traits may vary with the social landscape.
People Represent Social Resources for Each Other
- All organisms harvest resources from the environment.
- We harvest food, of course, but there are also many more kinds of resources.
- When we mate, we harvest the resources of the opposite sex.
- Both males and females harvest not only the genes of the opposite sex, but also the investment that the partner will make in the resulting
- Because humans are such a highly social species, social skills are required to harvest many of those resources we get from others.
- But one of the most important of those social skills is the ability to size up other people as potential cooperators or competitors:
members of the opposite sex as potential partners; newcomers to a group for their potential as leaders, workers, or troublemakers.
- Although the concept of intelligence has been around for thousands of years, scientists only began trying to measure it about 100 years
- Then it because necessary to think more carefully about just what intelligence is.
- There is no agreed upon definition.
- An old and often quoted quip has it that “intelligence is whatever intelligence test tests.”
Is Intelligence One Ability or Many?
- Both sides of this matter have been argued.
- Charles Spearman and others hold that there is a general or overarching intelligence, known as g that underlies and promotes various
special abilities, such as verbal, spatial, and so forth.
- This concept of g is supposed to correspond with what most people mean when they describe a person as smart or intelligent in
The Mating Mind
- Geoffrey Miller suggests that the very large human brain and high intelligence is resulted from sexual selection for good genes.
- Whereas deer evolved antlers to attract mates and defeat competitors, humans evolved high intelligence.
- He suggests that storytelling, humor, musical ability, and many other displays of intelligence serve as costly signals of fitness, especially
as it relates to brain function.
- Considering intelligence to be a sexually selected trait makes sense of the concept of g.
- Robert Sternberg suggests that current intelligence tests focus on analytical skills and ignore creative and practical intelligence.
- Probably everyone has known someone who was a whiz at school work but a complete failure at social skills. Multiple Intelligences
- Howard Gardner takes a different approach to intelligence in his widely influential theory of multiple intelligences.
- Although he is primarily interested in predicting school performance, he takes a broader view of intelligence than did previous workers.
1) Linguistic Intelligence - reading a book, writing a poem, understanding spoken words.
2) Musical Intelligence - ability to appreciate music, to sing, play instruments, compose, and so forth.
3) Logical-Mathematical Intelligence - solving math problems using formal symbols, balancing a checkbook, logical reasoning.
4) Spatial - getting from place to place, reading a map, packing suitcases into a car.
5) Bodily-Kinesthetic - sports, dancing.
6) Interpersonal - the ability to understand other people and their moods and motivations.
7) Intrapersonal - the ability to know one’s self and one’s feelings.
- Gardner proposes a number of criteria for a skill to be considered an intelligence.
1) The ability can be affected selectively by brain damage, as injury can produce aphasia (problems in speaking and understanding
speech) without affecting facial recognition.
2) There should be prodigies and idiots savants who display highly uneven distribution of skills. For example, we should expect to
find musical prodigies, or retarded persons who are nevertheless computationally adept and can say, for example, on which day of the
week March 10, 2017 will fall.
3) A plausible evolutionary basis (most important for our purpose).
- It recognizes that people act intelligently in situations other than school and therefore in ways not tested by traditional intelligence tests.
- We believe that the list of potential intelligences is quite large and would include face recognition, recognition of emotions in face,