Chapter 7: Cognition, Intelligence and Human Potential
Chapter 7: Cognition, Intelligence and Human Potential
Individual Differences
Not all individuals contribute equally or in the same way to the human condition. It was necessary for a substantial number of people with exceptional knowledge, problem-solving ability, and skills to work as a team to transform Manhattan from a forest to a metropolis. Until now, we have been focusing on differences between Stone-Age and technologically-enhanced cultures in order to appreciate extreme variations of the human condition. We have not discussed differences between the individual members of a culture. Not every member of the Nukak is the same height and weight. Not all members of the Nukak are equally skilled in blowing darts or fashioning necklaces. Not all college students are the same height and weight. Not all college students are equally proficient at shooting free throws or playing a musical instrument.
Psychology can be described as the science of individual differences. In the prior examples, psychologists would look to hereditary and experiential variables as potential causes of behavioral variation. Before we consider some controversial issues, it should prove helpful to place these issues within the larger context of how to formulate useful questions regarding individual differences. Frequently, by being specific and clear when defining terms, it is possible to shed light and avoid heat, even with the most contentious of topics. The scientific method is our best strategy for obtaining useful information to address difficult theoretical and practical questions.
I will use the game of basketball as an example since it is an internationally popular sport among adult males and females. The objective of the game is to shoot a 9-1/2–inch diameter sphere through an 18-inch circular rim located ten feet off the ground. The easiest, and most certain way to accomplish this, is to hold the basketball in your hands and “dunk” (or “stuff”) it through the rim (“hoop”). Basketball is a game where “size matters” (especially height). It is an advantage to be as close to the rim as possible.
One has to be over seven feet tall to be able to dunk a basketball while still standing on the ground. How likely is it that a person grows to be over seven feet tall? To answer this question, it would be necessary to measure everyone’s height and divide the number of people who are seven feet or more by the total. A more analytic approach would be to create a frequency distribution of the number of people of different heights.
Figure 7.18 Normal curves for height of women and men.
Figure 7.18 is an example of frequency distributions for the heights of samples of women and men from all over the world. The normal curve is a symmetrical bell-shaped curve characteristic of many variables in nature, including human characteristics and performance (e.g., height, reaction time, etc.). It is defined by a formula resulting in specific percentages of the area under the curve being relat