Endowment effect

Psychologist Bluma Zeignarik noticed that waiter hd trouble remembering orders after the food was delivered & the check was closed. 

To test her hypothesis she conducted a series of experiments to see if preventing participants from finishing a task could impact how well they remember them. 

These experiments confirmed that people tend to remember unfinished or incomplete tasks better than completed tasks. 

See the full study here :

Weber, E.U. (2010). What shapes perceptions of climate change? Wiley interdisciplanary Reviews : Climate change, 1(3), 332-342,

Want to know more about biases?

Affect Heuristic

Creativity Bias

Sunk Cost Fallacy

Default Effect