> that it references from across decades) that incentives can in some cases hurt.

To be clear, originally you said "extrinsic motivation can negatively impact intrinsic motivation". "Incentives can hurt" is a totally different statement; but I assume you still mean the original.

A short digression. As a scientist I think we should teach critical reading skills when it comes to science. This study has a bunch of things going against it:

1. It is published in an economics venue. This means the reviewers were economists, not psychologists. They had no clue about rewards, children, etc. They are experts in evaluating the model, not in what you want to know about, which is the part about humans.

2. You are relying on something in the paper that isn't the key contribution. You're relying on a short survey in the intro. No reviewer carefully read this and proposed updates. And even if they did, they were not the deciding factor in acceptance. Even if the intro was one-sided and mostly junk, if the model was amazing, the paper would be published. Papers are not evaluated based on their intros.

3. The paper is almost 25 years old, surveying material that is more than 25 years old. Science changes. A lot. The conclusions here could be totally different from the conclusions in a paper today because we have so much more evidence, higher quality studies, and better conceptual frameworks.

4. The authors have a particular goal: they want to show that there's a conflict between internal and external goals. This taints everything. They don't want to present an even-handed review, they literally want to make their case to a reader. I'm not saying this in some "conspiracy" sense. When I write a paper I want to argue my view, and put my view's worldview at the center, because I want to win people over.

All of this means that you should not be reading this paper in this way. It's the wrong paper, from the wrong time, with the wrong thesis, and you're looking in the wrong section.

We can do better!

Here is a review from 2020.
https://msofc.org/wp-content/uploads/2022/08/2020-Intrinsic-...

Let's compare with the points above.

1. It is published in Contemporary Educational Psychology. You can bet the reviewers here know the material, know the latest studies on child learning, etc.

2. The key contribution of the paper is a survey. This is what they are being evaluated for. You missed a paper? Nope, your survey is bad we don't accept you. You didn't fairly represent what that paper said, we don't accept you. etc. The paper is being evaluated by what you are looking for.

3. The survey is fairly current, 4-5 years is ok. You would expect a survey every that many years, or at least once per decade or so.

4. The authors might have biases, but not in this paper. This paper's goal is to present the state of the art. And reviewers aren't looking at the paper based on how well did their argue their point, they're looking at it based on how well they represented the state of the art.

All of this means that this paper should be read to find what you want to know. It's the right kind of paper, from the right time, with the idea of looking at the field and answering these kinds of questions, and we're looking in the main body of the paper.

Now, let's turn to the paper itself.

What it says is that extrinsic motivation is no longer seen as so alien from intrinsic motivation. That in the past 20 years there's a new framework that talks about internalizing extrinsic motivation.

https://al-kindipublisher.com/index.php/jeltal/article/downl...

The story is the same if you look at the paper above on language learning. The two types of motivation are not seen as opposites anymore.

You can keep reading by looking for "survey intrinsic extrinsic motivation teaching" and you'll find many more post 2020 papers. They all say the same thing. The field has changed. The two aren't opposites. Both are useful.