When people are paid by results their attitudes change

In reading about child motivation I have often come across the thesis that motivating children by means of rewards (basically payment) was not only not more effective, but might actually discourage them from the desired behaviour in general. I think the common example given is children being offered a reward to play with a certain toy (but one which would appeal to them anyyway) and then are monitored when they are left alone later with the same toy. The studies showed that children who had been provided with an incentive then didn't play much with that toy when the incentive was removed, whereas control children continued to do so. The interpretation was that the children now viewed playing with the toy almost as 'work', and hence had it was somehow excluded then from what there normal behaviour. The implication of course being that if such a reward mechanism is used, it will fail once the reward is removed, and does nothing to encourage the child to 'internalize' the behaviour, which is obviously what is actually needed.

But it is interesting to see that the same conclusion can apply to adults as well, and even more specifically, adults in the domain of economics, where rationality is still, even if bounded, largely assumed. Aditya Chakrabortty's Guardian article "When people are paid by results their attitudes change" is primarily focuses on how English rugby seems to have descended into selfish money grabbing, but references some interesting studies on this general phenomenon.

For example :
"Researchers now know a fair bit about how that shift works. Well over 100 tests have been carried out in which subjects are split in two and set some puzzles, next to a table with some glossy magazines. One group is paid $1 for each puzzle solved; the other does it for free. Time after time, the group working for nothing devote themselves to solving the puzzles. Those getting paid finish fast, then flick through the mags"

Or how when an Israeli daycare centre started charging parents for late drop-offs, the problem actually got worse:
"With tardiness now costing 10 shekels a pop, more parents should have turned up on time. But no. They came even later, because they saw the late pick-up now not as social embarrassment but as a service. And even when the centres stopped charging, the latenesses remained permanently higher. The introduction of a market norm had made its participants permanently more selfish."

In a society based on incentives and deterrents, this is something that needs to be taken seriously.

References (from Chakrabortty's article) :

A book review of "Not Just for the Money: An Economic Theory of Motivation" (Bruno Frey) which suggests:
"Extrinsic motivation involves external rewards, most usually associated by economists with the price system. Intrinsic motivation, or "behavioral motivation" as Frey also refers to it, comes from within. For both extrinsic and intrinsic motivation taken separately, the more we are motivated, the more effort we will put into a task. But research has shown that there may be situations when the two do not necessarily work together.
Frey invokes a familiar term to economists, ?crowding out? to describe the worst-case scenario. Crowding out occurs when the negative effect on intrinsic motivation of offering a monetary reward outweighs the positive extrinsic motivation. To use the labor market as an example, the result would be  reduction of work effort despite more pay. The profundity of this finding is that the result runs counter to the predictions of economic theory."

The paper on the Israeli daycare centre.
Abstract :
"The deterrence hypothesis predicts that the introduction of a penalty that leaves everything else unchanged will reduce the occurrence of the behavior subject to the fine. We present the result of a field study in a group of day-care centers that contradicts this prediction. Parents used to arrive late to collect their children, forcing a teacher to stay after closing time. We introduced a monetary fine for late-coming parents. As a result the number of late-coming parents increased significantly. After the fine was removed no reduction occurred. We argue that penalties are usually introduced into an incomplete contract, social or private. They may change the information that agents have and therefore the effect on behavior may be opposite than expected. If this is true, the deterrence hypothesis loses its predictive strength, since the clause 'everything else is left unchanged' might be hard to satisfy. "