Intrinsic vs Extrinsic Motivation: Why Rewards Backfire and What to Do Instead

A parent in one of my workshops once told me proudly that she paid her P4 son HK$20 for every A he got on a test. He was, she said, extremely motivated. He was also, she admitted when I asked, completely uninterested in studying anything that wasn't being assessed.

I've thought about that boy often. He had learned the system perfectly. He had also learned, implicitly, that learning had no value beyond its monetary yield.

The Research That Should Have Changed Everything

In 1973, psychologists Mark Lepper, David Greene, and Richard Nisbett ran an experiment that became one of the most cited studies in motivational psychology. They observed children who naturally enjoyed drawing — intrinsically motivated artists. Then they divided the children into three groups. The first group was told they'd receive a "good player award" for drawing (expected reward). The second group received a surprise reward after drawing (unexpected reward). The third group received nothing.

Two weeks later, when drawing materials were made available freely, the children who had been promised rewards spent significantly less time drawing than either the surprise reward group or the no-reward group. The intrinsic motivation had been damaged by the extrinsic reward.

This phenomenon — now called the overjustification effect — has been replicated extensively across cultures and ages. A 2018 meta-analysis in Psychological Bulletin covering 128 studies confirmed that tangible rewards consistently undermine intrinsic motivation for activities that were already interesting. The effect is strongest for tasks requiring creativity or deep thinking — precisely the kind of tasks academic learning involves.

Why This Is Particularly Relevant in Hong Kong

Hong Kong parents operate in an environment where extrinsic incentivisation is pervasive and normalised. I understand why. When every parent at the school gate seems to be offering rewards, and when the visible metric of success is a test score, motivation-by-reward feels rational.

But consider the endgame. Children who are extrinsically motivated through primary school reach secondary school and suddenly face work that is too cognitively demanding to be produced adequately by reward-seeking behaviour. The depth of engagement required for S4-S6 level work — the sustained intellectual effort over months — is something that no reward system can reliably purchase. This is often when parents describe their teenager as having "given up." But the groundwork for that disengagement was laid years earlier.

My P3 daughter went through a phase of only doing homework if I promised television time afterward. I had created that dynamic, and I had to unpick it. It took about three months of deliberate change. I'm sharing this not as a success story, but as evidence that the pattern is easy to establish and genuinely effortful to reverse.

Not All Rewards Are Equal

Here's where it gets more nuanced, because the research does not say "never reward."

What consistently damages intrinsic motivation:

• Tangible, expected rewards tied to completion or performance of an already-interesting task
• Surveillance and controlling evaluation ("I'll be watching to make sure you do it")
• Rewards that communicate the activity has no value in itself

What does not damage intrinsic motivation, or can even support it:

• Unexpected, surprise praise or recognition
• Verbal praise that is specific and informational rather than controlling ("That explanation you wrote was really clear — the way you sequenced your reasons helped me understand your thinking")
• Rewards for activities the child finds genuinely tedious and would not engage with otherwise (though this remains a short-term fix)
• Rewards in social contexts — family recognition, sharing achievements — which support belonging rather than external control

The key distinction is between controlling rewards and informational feedback. Controlling rewards shift the perceived cause of behaviour from internal to external. Informational feedback — "you found the difficult approach and it worked" — adds to the child's sense of competence and autonomy without hijacking the internal motivation.

What Intrinsic Motivation Actually Needs

Self-determination theory, developed by Edward Deci and Richard Ryan over four decades, identifies three psychological needs that, when met, support intrinsic motivation robustly:

Autonomy — a sense that one's actions are self-directed. This does not mean no rules. It means children have meaningful choice within appropriate constraints. Letting a child choose the order in which they do homework, where they sit, which maths problems to tackle first — these small choices matter more than they seem.

Competence — the experience of mastery and growth. This requires that challenges be calibrated appropriately. Too easy, and there's no interest. Too hard, and there's anxiety and avoidance. The "flow" zone described by Csikszentmihalyi is real — and it's where genuine motivation lives.

Relatedness — connection to people who care about the child's development. A child who feels genuinely seen and valued by a parent or teacher is more likely to engage with what that person finds important. This is why the relationship is always prior to the strategy.

Practical Steps for Parents

If you're using a reward system right now, I'm not suggesting you abolish it tomorrow. Abrupt withdrawal of anticipated rewards can create its own problems. But here's a gradual path:

Start building a language around the activity itself. "Did you find anything interesting in that chapter?" replaces "Did you finish?" Interest needs to be noticed and named to grow.

Introduce genuine choice where possible. Within the non-negotiable of homework completion, there is usually more latitude than we offer. Use it.

Reduce surveillance. Hovering while a child works communicates distrust and shifts focus from the task to your presence. For most healthy children, giving them space to complete work independently — with a check-in afterward — produces better engagement than watchful oversight.

When the work is genuinely unpleasant, acknowledge it honestly. "This is quite repetitive — let's just get through it together" is more respectful than pretending everything is exciting. Authenticity maintains the relationship. The relationship maintains the motivation.

I paid my daughter back for those television sessions with something better eventually: an afternoon at the bookshop where she could choose anything she wanted, for no reason except that she'd been working hard and I wanted her to know I saw it. She still talks about that afternoon. The television she barely remembers.