First off, what exactly is your source?

Secondly, your taking an obscure finding of what seems to be extrinsic vs intrinsic motivations and incorrectly extrapolating it. Your method of withholding goals has been demonstrated countless times to lead to people less likely to pursue their goals.

The thing is, is that when we tell other people our goals, we receive a sense of gratification from that goal even though we haven't achieved it yet. Therefore, we are less likely to fulfill that goal.

For instance, lets say Leroy wants to get ripped like the people he sees in the muscle magazines all the time. He tells Suzy. She's really happy for him. Leroy feels a sense of gratification from this because now she sees him as becoming a ripped guy. He hasn't even achieved his goal yet, but it almost feels like he did. Now he doesn't have as much motivation to get ripped like he did before. Furthermore, if he doesn't achieve his goal, it's going to show Suzy he isn't a strong individual. Literally and figuratively.

On the contrary, if Leroy doesn't tell anyone his goal of getting ripped, he is more likely to achieve it. By not telling Suzy, when he actually does get ripped, she's going to be really impressed, where before, it's already expected of him and she wouldn't be nearly as impressed. He's always looking forward to the end result, and is a lot more likely to achieve it.

In one clever study, they had students interested in becoming Psychologists list two activities that they would perform in the next week to help them achieve that goal. Half of the people handed what they wrote to the experimenter who read it over and acknowledged reading what they had written. The other half were told that the exercise of writing down their intentions was given to them in error, and that nobody would be looking at it. The following week, all of the participants were contacted again and were asked to remember the goals they had written down the previous week and then to write down how much time they had spent on those activities. The people whose goals were read by the experimenter actually spent less time pursuing those activities than the people whose goals were not read. A number of follow-up studies were presented as well that ruled out other explanations for this finding.

Receiving compliments while striving for a goal are much more effective than receiving compliments if you're close to or already have achieved your goal.

People have a desire to look consistent through their words, beliefs, attitudes and deeds.

When relating to identity goals this research suggests that if we don't tell people our goal, we use our actions to convey our goals to people.

In the first case, four in twenty times the second accomplice could "steal" the radio without challenge.