Geir Overskeid (1999) Factual Knowledge and Problem-solving Ability:. Psycoloquy: 10(011) Brain Expertise (2)

Volume: 10 (next, prev) Issue: 011 (next, prev) Article: 2 (next prev first) Alternate versions: ASCII Summary
Topic:
Article:
PSYCOLOQUY (ISSN 1055-0143) is sponsored by the American Psychological Association (APA).
Psycoloquy 10(011): Factual Knowledge and Problem-solving Ability:

FACTUAL KNOWLEDGE AND PROBLEM-SOLVING ABILITY:
NOT EXPERTISE, BUT PERHAPS STILL RELATED TO BRAIN SIZE
Commentary on Skoyles on Brain-Expertise

Geir Overskeid
Program in Economic and Organizational Psychology
Norwegian School of Management BI
P. O. Box 4636 Sofienberg
0506 OSLO NORWAY
http://www.bi.no/users/fgl97015/index.htm

geir.overskeid@bi.no

Abstract

Skoyles's claim that the large brains of modern humans are related to our capacity for developing expertise seems well founded. However, there are other possible candidates for this role. I discuss two of them, problem-solving ability and the ability to gather and remember large amounts of facts.

Keywords

brain size, brain imaging, evolution, expertise, hemispherectomy, Homo erectus, individual differences, intelligence, IQ, language, microcephaly, MRI volumetrics, psychometrics.
1. Skoyles's (1999) interesting target article points out the possibility that evolution expanded the brain size of modern humans in order to increase our capacity to develop expertise. This hypothesis has merit, and should be followed up by more detailed studies of the relationship between brain size and capacity for expertise. Few psychologists should have problems accepting Skoyles's assertion that psychometrically measured IQ leaves out cognitive functions that are relevant to intelligent behavior. Nevertheless, the question arises why expertise has been singled out as the prime explanation for our growing brains. Two other candidates that leap to mind are problem solving ability_ and the capacity to gather and remember factual knowledge_.

2. The word "problem" has been defined in different ways by different authors. Mayer's (1990, p. 284) definition contains the essential elements, and should be uncontroversial: "A 'problem' exists when a situation is in a given state, the problem solver wants the situation to be a goal state, and there is no obvious way of transforming the given state into the goal state." In a description that should be equally uncontroversial, Ericsson & Hastie (1994) say that having expertise means having "domain-specific representations and working memory skills that support specialized planning, reasoning, and evaluation." A task is only a problem when there is no obvious way of reaching the goal state. Due to their sophisticated skills, which take years to develop, experts see obvious ways of performing tasks that are problems to other people.

3. It is true that the capacity to develop expertise has obvious survival value, as maintained by Skoyles. It can nevertheless be argued that the ability to solve problems, which is something else, may have at least the same value to a hunter-gatherer. Expertise is for stable environments, but problem solving ability is for adapting to new and unknown circumstances: Communicating with members of another culture, in order to promote co-operation or avoid being harmed; hunting a new kind of animal; finding out how to grow a new type of crop; discovering how to avoid or cure disease -- indeed, dealing with all types of unknown situations, from little things to acute and life-threatening crises. If one has not encountered a certain culture or seen someone suffer from a certain disease before, one may not have much expertise that can be brought to bear on these problems. In addition, experts tend to become victims of mechanization effects that may make them less efficient than non-experts at solving new types of problems (Baron, 1994). Hence, there is little doubt that the ability to solve problems has had survival value.

4. But is not problem solving ability more or less the same as IQ? It does not seem to be. Several studies indicate that the correlation between IQ and the ability to solve problems is low (Dörner, 1986; Helstrup, 1988; Yama, Umemoto, & Kinjo, 1990, but see Raaheim, 1989).

5. No direct evidence appears to exist regarding the relation between brain size and expertise. There is evidence to indicate that problem solving ability may be related to brain size in normal humans, however. First of all, as Skoyles (1999) notes, men have somewhat larger brains than women. Given that men tend to be bigger than women, this is not surprising. However, there seems to be a sex difference in brain weight that does not disappear when body surface area and height is controlled for. For example, Ankney (1992) found a mean difference of 100 g, favoring men, among 168 cm tall whites (the average height for men and women combined in his sample of 1261 American adults) (see also Rushton & Ankney, 1996). Sex hormones seem to play a role: The brains of female rats have been found to grow heavier after ovariectomy, with substantial increase in dendritic arbor and spine density (Stewart & Kolb, 1994). Several studies have found that women do worse than men on creative problem solving tasks (e.g., Kaufmann, 1979; Maier, 1970), as well as on tasks that may be related, such as mathematical reasoning (Stumpf & Jackson, 1994; Kimura, 1993), and spatial problems (Voyer, Voyer, & Bryden, 1995).

6. Solving a problem means mastering a new situation. There are strong indications that developing a capacity for problem solving is related to increased brain weight: Several studies of animals reared in enriched environments, with many opportunities to master new situations through problem solving, show not only clear changes in cortical morphology, but also increases in overall brain weight. Rats, for instance, consistently show brain weight increases in the order of 7% - 10% after 60 days (Kolb & Whishaw, 1998), though some of this increase could result from increased physical activity (cf. Neeper, Gomez-Pinilla, Chol, & Chotman, 1995).

I. KNOWING FACTS

7. It seems, then, that both expertise and problem-solving ability may have played a role in increasing the brain size of humans. However, at least one more candidate needs to be considered: The ability to consciously remember large quantities of facts from a wide variety of areas.

8. Expertise has a limited area of applicability. Leading a hunter-gatherer life in a way that increases one's probability of surviving and spreading one's genes may often call for being a jack of all trades, not just a master of one. To some extent, factual knowledge can make up for the many years of task-specific practice that is a prerequisite of expertise (and no one can have expertise in very many fields). Furthermore, being knowledgeable gives one an opportunity to teach -- thereby forging social bonds and gaining prestige. Knowledge also opens up possibilities for social climbing; and, perhaps most important: To a person with substantial factual knowledge, many potential problems never become problems -- knowledgeable people can draw on what they know: General principles and heuristics, as well as trivia. It should be noted that across several areas, men, who, as we have seen, tend to have bigger brains, ceteris paribus, also tend to know more facts than do women (Dale, Saarinen, & MacCabe, 1995; Halpern, Haviland, & Killian, 1998; Stromsnes, 1995)

9. This brief commentary does not purport to show that the large brain of modern humans has been selected to help us solve problems and remember facts. Nor does it demonstrate that a bigger brain will give individuals an increased problem-solving ability, a greater interest in factual knowledge, or better semantic memory. Furthermore, some of the arguments are based on findings indicating a sex-related difference in the brain size of humans, even after controlling for height and body surface. It should therefore be noted that women seem to excel in fields that may be related to survival. For instance, their verbal skills are typically superior to those of men (e.g., Halpern, 1997), even though their brain weight, other things equal, seems to be somewhat lower. One explanation for this may be the finding that women have slightly more extensive dendritic arbors in Wernicke's area than do men (Jacobs, Schall, & Scheibel, 1993).

10. All in all, the evidence discussed gives little reason to doubt the reasoning of Skoyles (1999). It does seem, however, that we should consider the possibility that our capacity for expertise may not have been the only advantage related to humans' developing larger brains.

REFERENCES

Ankney, C. D. (1992). Sex differences in relative brain size: The mismeasure of woman, too? Intelligence, 16, 329-336.

Baron, J. (1994). Thinking and deciding (2nd ed.).Cambridge, England: Cambridge University Press.

Dale, B. E., Saarinen, T. F., & MacCabe, C. L. (1995). World images, geographic knowledge, and gender differences: A case study of Norway (Papers from The Department of Geography, University of Trondheim, New Series A, No. 8). Trondheim, Norway: University of Trondheim, Department of Geography.

Drner, D. (1986). Diagnostik der operativen Intelligenz [Diagnosis of operative intelligence]. Diagnostica, 32, 290-308.

Ericsson, K. A., & Hastie, R. (1994). Contemporary approaches to the study of thinking and problem solving. In R. J. Sternberg (Ed.), Thinking and problem solving (pp. 37-79). San Diego, CA: Academic Press.

Halpern, D. F. (1997). Sex differences in intelligence: Implications for education. American Psychologist, 52, 1091-1102.

Halpern, D. F., Haviland, M. G., & Killian, C. D. (1998). Handedness and sex differences in intelligence: Evidence from the medical college admission test. Brain and Cognition, 38, 87-101.

Helstrup, T. (1988). The influence of verbal and imagery strategies on processing figurative language. Scandinavian Journal of Psychology, 29, 65-84.

Jacobs, B., Schall, M., & Scheibel, A. B. (1993). A quantitative dendritic analysis of Wernicke's area in humans. II. Gender, hemispheric, and environmental factors. Journal of Comparative Neurology, 327, 97-111.

Kaufmann, G. (1979). The explorer and the assimilator: A cognitive style distinction and its potential implications for innovative problem solving. Scandinavian Journal of Educational Research, 23, 101-108.

Kimura, D. (1993). Sex differences in the brain. In Mind and brain: Readings from Scientific American Magazine (pp. 79-89). New York: W. H. Freeman.

Kolb, B., & Whishaw, I. Q. (1998). Brain plasticity and behavior. Annual Review of Psychology, 49, 43-64.

Maier, N. R. F. (1970). Problem solving and creativity in individuals and groups. Belmont, CA: Brooks/Cole.

Mayer, R. E. (1990). Problem solving. In M. W. Eysenck (Ed.), The Blackwell dictionary of cognitive psychology. Oxford, England: Blackwell.

Neeper, S. A., Gomez-Pinilla, F., Chol, J., & Cotman, C. (1995). Exercise and brain neurotrophins. Nature, 373, 109.

Raaheim, K. (1989). The dilemma of the intelligent problem solver. In

I. A. Bjorgen (Ed.). Basic issues in psychology (pp. 211-220).

Sreidgrend, Norway: Sigma.

Rushton, J. P., & Ankney, C. D. (1996). Brain size and cognitive ability: Correlations with age, sex, social class, and race. Psychonomic Bulletin & Review, 3, 21-36.

Skoyles, J. R. (1999). Human evolution expanded brains to increase expertise capacity, not IQ. PSYCOLOQUY 10(2). ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/1999.volume.10/ psyc.99.10.002.brain-expertise.1.skoyles http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?10.002

Stewart, J., & Kolb, B. (1994). Dendritic branching in cortical pyramidal cells in response to ovariectomy in adult female rats: Suppression by neonatal exposure to testosterone. Brain Research, 654, 149-154.

Stromsnes, K. (1995). Kjonn og politisk kunnskap [Sex and political knowledge]. In N. C. Raaum (Ed.), Kjnn og politikk (pp. 244-275). Oslo, Norway: TANO.

Stumpf, H., & Jackson, D. N. (1994). Gender-related differences in cognitive abilities: Evidence from a medical school admissions testing program. Personality and Individual Differences, 17, 335-344.

Voyer, D., Voyer, S., & Bryden, M. P. (1995). Magnitude of sex-differences in spatial abilities: A metaanalysis and consideration of critical variables. Psychological Bulletin, 117, 250-270.

Yama, H., Umemoto, T., & Kinjo, Y. (1990). Aptitude, task performance, and solution strategy of the three-term series problem. Japanese Psychological Research, 32, 101-106.


Volume: 10 (next, prev) Issue: 011 (next, prev) Article: 2 (next prev first) Alternate versions: ASCII Summary
Topic:
Article: