Story of Psychology - Morton Hunt [157]
In addition to all the uses made of IQ testing, it also is an essential tool for various kind of neurological research. Psychologists have long wondered whether the brains of highly intelligent people differ, physically, from those of average people. A new study initiated by the National Institute of Mental Health, relying on brain scans by magnetic resonance imaging over a period of seventeen years, has shown that the cortex— the outer sheet of neurons covering the brain that is the seat of many higher mental processes—grows thicker than average in highly intelligent children as they age and then thins out later, ending up even thinner than average. “This is the first time that anyone has shown that the brain grows differently in extremely intelligent children,” says Paul M. Thompson, a brain-imaging expert at the University of California at Los Angeles. Apparently, the brains of the highly intelligent children are rewiring themselves, developing fruitful connections among the neurons and later pruning out redundant ones, thus operating more effectively during childhood and remaining more effective in adulthood. And here’s the point: All the data on the different growth of these children’s brains would tell us nothing about intelligence were it not for the IQ tests and scores taken along with the scans.69
The IQ controversy has raged, died down, and raged again; politics beclouds science, and science is used for political ends. The struggle continues and shows no signs of ending, but lineal descendants of the early intelligence tests, now greatly modified and more nearly “culture-fair” than the early tests, are widely used in schools, institutions, the military, industry, and elsewhere.
Whatever one calls them, and whatever one’s stance on intelligence testing, the fact remains that mental measurement is useful, is beneficial to society (though not in the way Goddard and Terman had in mind), and remains one of psychology’s major contributions to modern life in America and most other developed nations.
* Literally, “weaklings.” Later, the term came to be translated as “morons,” a word that did not yet exist.
NINE
The
Behaviorists
A New Answer to Old Questions
By the late 1890s, humankind, after some twenty-four centuries of speculation about how the mind works, seemed on the verge of understanding it. The followers of Wundt and James were, in their different ways, introspectively examining their conscious sensations and thoughts; Freud was peering into the murky depths of his own unconscious and that of his patients; and Binet was preparing to measure the growth of the intellect throughout childhood.
Why, then, were a number of psychologists and physiologists playing little tricks on animals that could tell nothing about their inner experiences, and calling it psychological research?
How could it advance the understanding of the human mind to offer a baby chick two kinds of caterpillars, one of which presumably tasted bitter? (“Presumably” because it appears that the researcher himself never tasted it.) Or to soak some kernels of corn in quinine, others in sugar water, dye them different colors, and strew them before chickens? The baby chicks pecked at both kinds of caterpillar and shortly began to avoid the bitter ones, and the chickens soon ate only the sweetened kernels of corn, but what did any of that have to do with human learning?1
How could any of the great questions of psychology be answered by putting a hungry cat in a slatted “puzzle box” from which it could escape only by stepping on a treadle that opened a door? After placing the cat inside and latching the door, the researcher set a scrap of fish outside. The cat, galvanized by the sight and smell of the fish, pressed its