sent in by The Happy Humanist

An excerpt from "Introduction to Psychology" 4th ed. by James W. Kalat:

"Beginning with the Renaissance period in Europe, people began looking for scientific explanations for the phenomena they observed. One of the key points of this Scientific Revolution was a shift toward seeking the immediate causes of an event (what led to what) instead of the final causes (the ultimate purpose of the event in an overall plan). Scientists analyzed the motion of objects in terms of pushes and pulls, and other laws of nature. That is, they made an assumption that everything that happens has a cause, or determinant, in the observable world.

Is the same true for human behavior? We are, after all, part of the physical world. Your brain and mine are made of chemical compounds subject to the same laws of nature as anything else. According to the determinist assumption for human behavior, everything we do has a cause.

Clearly, at least some of those causes lie within us. A person walking down a mountainside is not the same as a rock that is rolling or bouncing down the same mountainside. The point of psychological determinism is that even when you make comoplex decisions about how to get down a mountainside safely, your decision is a product of the combined influence of your genetics, your past experiences, and the current environment. That is, just as an engineer can design a robot to consider information and make appropriate decisions, your genetics and experience have programmed you to make appropriate decisions.

Logically, the opposite of determinism would be indeterminism - the idea that events happen randomly with no cause at all. When we are discussing psychology, however, few people argue that important events are truly random or indeterminate. Rather, opponents of determinism defend a position called free will, a difficult view to describe. To some extent, it is merely a rejection of determinism, claiming that people sometimes make decisions not controlled by their genetics, their past experiences, or their environment. But what is left besides genetics and environment? The answers here are generally vague, but accompanied by an insistence that our decision-making processes are in some way beyond the reach of the natural sciences.

The test of determinism is ultimately empirical: If everything we do has a cause, our behavior should be predictable. To a large extent, it is. For example, suppose a number of students are studying in various rooms of a campus building when they hear an announcement: "A fire has broken out in this building. By the time we bring the fire under control, the smoke and fumes may become hazardous. We therefore request that everyone leave the building." I can predict that almost everyone will promptly leave the building. I can make an even more accurate prediction if I know something about the individual students: I can predict that everyone will leave the building except those who are hearing-impaired, those who do not understand English, and those who have been advised by a friend that "every year at about this time someone says to leave the building because of a fire, but it's just a silly exercise to show that psychologists can predict your behavior, so be sure to ignore the warning."

In other situations, however, you might object that no one could possibly predict your behavior, no matter how much he or she knew about you. For example, no one could predict what you will choose to eat for lunch tomorrow or which color of sweater you will buy or how many pages of this book you will read before you quit to do something else.

You are right; certain details of your behavior will probably remain forever unpredictable. However, that unpredictability does not imply a lack of causes. Physicists and mathematicians today talk about chaos - the complex effects that result from the influence of many small causes. For example, imagine that I drop a golf ball at the top of a hilly road and measure the exact point at which it eventually comes to rest. Then I take the ball back to the same location at the top of the hill and drop it in the same way as I did the first time. Will it eventually land in the same place as it did the first time? Very unlikely. The first bounce or two will be in nearly the same places as before, but with each succeeding bounce, the ball will veer farther and farther from its original route. The discrepancy does not indicate that the ball has violated the principles of physics; it simply shows the cumulative influence of an enormous number of tiny influences. Similarly, when you are deciding what to eat for lunch or which sweater to buy, your behavior is subject to so many tiny influences that your choice may be no more predictable than the final bounce of that golf ball. The unpredictability stems from the great number of small causes, not from a lack of causes.

Like most scientifically oriented psychologists, I, your author, believe in the concept of determinism. However, let me concede an important point. You will recall that in the introduction to this chapter I said that we all sometimes state something with confidence when it really is only an assumption. Here is such a case. Researchers assume that every behavior has a natural cause, because that assumption seems to work, and because the only way to test the assumption is to see how far we can go with it before we find some limit. Still, to be honest, it is an assumption and not a certainty."

Okay, I'll admit I took the easy way out and quoted verbatum from a textbook. So sue me. Anyway, if there are any religious fundamentalists out there who would like to argue that free will exists, let's do it. Let the debate begin.