Reiss, a professor of psychology at Ohio State University , argues that a diverse range of human motivations can't be forced into these categories of intrinsic and extrinsic motivations. Psycholgists say intrinsic motivations are those that arise from within - doing something because you want to - while extrinsic motivations mean people are seeking a reward, such as money, a good grade in class, or a trophy at a sporting event.
"They are taking many diverse human needs and motivations, putting them into just two categories, and then saying one type of motivation is better than another," said Reiss, who outlines his argument in the current issue of the journal Behavior Analyst.
"But there is no real evidence that intrinsic motivation even exists."
The issue is more than academic, Reiss said. Many sports psychology books, and books advising how to motivate students and business people, tout the value of intrinsic motivation and warn that extrinsic rewards can undermine people's performance.
The argument is that people should do something because they enjoy it, and that rewards only sabotage natural desire.
"There is no reason that money can't be an effective motivator, or that grades can't motivate students in school," he said. "It's all a matter of individual differences. Different people are motivated in different ways."
Reiss has developed and tested a theory of motivation that states there are 16 basic desires that guide nearly all meaningful behavior, including power, independence, curiosity, and acceptance. Whether you agree there are 16 desires or not, he said there is not any way to reduce all of these desires to just two types.
In addition to trying to fit all motivations into two types, Reiss said proponents of intrinsic motivation are also making value judgments by saying some types of motivation are better than others.
"For example, some people have said that wealth and materialism lead to inferior quality happiness, but there is no real proof of that," he said.
"Individuals differ enormously in what makes them happy - for some competition, winning and wealth are the greatest sources of happiness, but for others, feeling competent or socializing may be more satisfying. The point is that you can't say some motivations, like money, are inherently inferior."
In the article, Reiss points to some of the problems he sees with the theories and studies connected to intrinsic motivation. One problem is that people who tout the value of intrinsic motivation have several different definitions for what that means, and these definitions change depending on circumstances.
One common definition, for example, is that intrinsic motivation is that which is inherently pleasurable, while extrinsic motivation is not. For example, the argument is that children are naturally curious and enjoy learning for the joy it brings them. Grades, they argue, are an extrinsic reward that fosters competition and makes learning less pleasurable.
However, Reiss said his research has found people show a wide range of curiosity - some people are very curious and enjoy spending a great deal of time learning on their own. However, many people are not very curious and don't enjoy learning for its own sake.
"There are many children for whom the important reward to them is the grades they get, the competition among classmates," Reiss said. "This goes against what some psychologists say, who think competition is bad and a non-competitive attitude is good, and that learning and curiosity are intrinsic values that everyone shares. They are pushing their own value system on to everybody."
Another way of defining intrinsic motivation is the means-end definition, which says intrinsic motivation is doing what we want, whereas extrinsic motivation is doing something to get something else. For example, some might argue that children playing baseball are intrinsically motivated by the joy of playing, while a professional baseball player is extrinsically motivated, by money and championships.
But Reiss said this definition confuses means and ends. A child playing baseball may be satisfying his need for physical exercise, while the professional player is satisfying his parental instinct by providing a good income for his family.
For children and professionals, baseball is a means to two different ends.
Reiss also criticized many of the studies which proponents say prove the existence of intrinsic motivation, and how it can be undermined by extrinsic rewards.
For example, many studies have purportedly shown how people who enjoy doing a specific activity - such as children who enjoy drawing - do that activity less after they are offered rewards. But when the results show the subjects continue the activity even after the rewards are offered, the researchers have argued that this just shows the subjects expect to get a reward and no longer are intrinsically motivated.
"The results are always turned around to prove their hypothesis."
Also, researchers have assumed that rewards simply make people less interested in the intrinsic joys of an activity. But Reiss said many of these studies haven't considered the possibility that the negative effect of rewards has nothing to do with intrinsic or extrinsic motivations. Instead, rewards may cause some people to pursue an activity less because of the negative feelings they cause, such as performance anxiety. Avoiding an activity because of performance anxiety related to a reward is not the same as avoiding it simply because the reward undermines intrinsic motivation.
"Too many studies that supposedly prove intrinsic motivation have serious flaws in logic, or too many important uncontrolled variables," he said. "There needs to be more scientific rigor."
Contact: Steven Reiss, (614) 292-2390; Reiss.firstname.lastname@example.org
Written by Jeff Grabmeier, (614) 292-8457; Grabmeier.email@example.com