The Candle Problem & Understanding Human Motivation

Incentives, while effective for routine tasks, offer little help in promoting creative problem-solving. Fostering employee engagement through autonomy, mastery, and purpose drives productivity. Organizations that prioritize these factors can unlock the full potential of their employees.

Table of Contents


In 1945, renowned German psychologist Karl Duncker devised a cognitive performance test to investigate individuals’ problem-solving approaches when presented with a collection of commonly used objects. In this experiment, participants were tasked with securing a candle onto a cork board wall in a manner that prevents the wax from dripping onto a table below. To aid in this endeavor, the participants were provided with a box of thumbtacks and a set of matches.

Karl Duncker's Candle Problem
Karl Duncker’s Candle Problem

Duncker’s Observations

Duncker’s observations revealed that only a small fraction of individuals were able to solve the candle problem in its original form. Many participants attempted unsuccessful approaches, such as melting the candle on the sides using the matches or affixing the lit candle to the board using the thumbtacks. Only a few participants discovered the solution of perceiving the box of thumbtacks as a viable tool. Interestingly, when the box was emptied, more participants recognized that they could affix the box to the wall using the thumbtacks and place the candle within it. Duncker referred to this mental obstacle as “functional fixedness,” a cognitive bias that hinders individuals from perceiving objects beyond their intended purpose.

The Limitations of Incentives for Fostering Creativity

In 1962, Sam Glucksberg conducted similar experiments to Duncker’s, but with some variations. Glucksberg introduced incentives into the equation and divided participants into two groups. One group was offered a monetary reward for solving the original candle problem, while the other group was not. The incentivized group was informed that the top 25% fastest solvers would receive $5, and the quickest solver would be awarded $20. Surprisingly, the results showed that the incentivized group took longer to arrive at a solution compared to the non-incentivized group. Glucksberg then repeated the experiment after emptying the box of thumbtacks. In this scenario, the incentivized group performed better than they did previously. These findings suggest that while incentives may be beneficial for problems that do not require creativity, they offer little help when it comes to challenges that demand “out of the box” thinking.

Understanding Human Motivation

As highlighted by author and researcher Daniel H. Pink in his book “Drive: The Surprising Truth About What Motivates Us”, the secret to driving intrinsic motivation within organizations relies on 3 key factors: Autonomy, Mastery and Purpose.

  • Autonomy refers to the need to control one’s own life and work. Individuals feel most motivated when they have the freedom to decide what they do, when they do it, how they do it, and with whom they collaborate.
  • Mastery involves the desire to continuously improve in a meaningful area. The motivation stems from the pursuit of progress itself, emphasizing the process rather than solely focusing on the end goal.
  • Purpose represents the yearning to contribute to something greater than oneself. If individuals lack a clear understanding of the reasons behind their actions, their motivation will likely dwindle.

By providing employees with autonomy, mastery, and purpose, organizations can create an environment that fosters their growth and maximizes their potential.


In conclusion, Karl Duncker’s and Glucksberg’s experiments with the Candle Problem sheds light on the cognitive biases that impede creative problem-solving. It highlights the limited effectiveness of incentives in fostering creativity. As Dan Pink reminds us, the secret to intrinsic human motivation relies on autonomy, mastery, and purpose. By aligning organizational practices with these principles, companies can unlock the full potential of their employees.