Why everything takes longer than you expect

Written by Carl Davidson, Chief Social Scientist, Research First

Rosabeth Moss Kanter, the Director of the Harvard University Advanced Leadership Initiative, once said that “the middle of every successful project looks like a disaster”. I’ve always loved that idea, but the view from social science tends to be that it’s the start of projects where the problems lie. When we estimate how long a project will take, it seems we’re wired to chronically underestimate the time needed. This is such a common problem that it is known as ‘The Planning Fallacy’. It’s expressed even better in Hofstadter’s Law. Named after the cognitive scientist, Douglas Hofstadter, this law states that “it always takes longer than you expect, even when you take into account Hofstadter’s Law”.

The important part for our purposes is that ‘always’ part, because we fall into this planning trap over and over again. It’s not that we can’t see that projects tend to miss deadlines and budgets, just that we think the next one will work better.

This provides a wonderful lens into one of the most counteractive findings from psychology – that none of us is much good at predicting how we’re going to feel in future. Predicting future emotions is called ‘affective forecasting’ and all the research evidence shows that its rarely straightforward. The problem isn’t, as the Rolling Stones noted, that we can’t always get what we want, it’s that we rarely know what we need. This has real implications for your wellbeing because it shows that while right now you might think a new house, spouse, or waistline will make you happy, the chances are they won’t. Or at least not in the way you were hoping.

The gap between what we think we’ll feel when we make our predictions and what we actually end up feeling is called, imaginatively, ‘the impact bias’. This bias has two parts – intensity and duration. This describes how achieving our goals doesn’t make us as happy as we expected (the intensity of the emotion), and how that happiness doesn’t last as long as we anticipated (the duration of the emotion).

We fail to understand how we’ll feel in future, because, as Psychology Today put it, “we have trouble seeing through the filter of the now”. It’s the same with predicting how long projects will take. What seems to be at fault here is a cognitive bias known as ‘The Optimism Bias’. This describes how we overestimate the likelihood of positive outcomes and underestimate negative ones. If you don’t think that sounds like you, it might surprise you to read that it is “one of the most consistent, prevalent, and robust biases documented in psychology and behavioural economics”. Given this, it’s no surprise that all of us at some point will get to enjoy “the whooshing noise” deadlines make as they go by.

As a result, at the start of every new project we manage to convince ourselves that, this time, the best-case scenario will be realised. When we ‘plan’ we tend to focus on the details of the project steps rather than simply reflecting on how long it took to do something similar previously. But with projects as with so much in life, thinking about past performances rather than best cases is usually the smarter bet.



I’ve used the Kanter quote for years, and it’s all over the internet, but it’s not really clear to me where it comes from. It might be that the original is actually “everything feels like a failure when you are in the middle”. If any of you know the original and the source, please get in touch.

‘The Planning Fallacy’ is another brainchild of Daniel Kahneman and Amos Tversky. It’s covered well in Kahneman, D. (2011).Thinking, Fast and Slow (New York: Farrar, Straus and Giroux). It’s also worth reading Roger Buehler, Dale Griffin, and Michael Ross’s (1994) “Exploring the Planning Fallacy Journal of Personality and Social Psychology. Vol. 67, No. 3. 366-381.

You can read about Hofstadter’s Law in his wonderful (1980) Gödel, Escher, Bach: An Eternal Golden Braid, Vintage Books Edition, p. 152 or find a great summary in Oliver Burkeman’s (2008) “Why everything takes longer than you think” (The Guardian, August 2nd, 2008).

The best place to start reading about The Optimism Bias is Tali Sharot’s (2011) “The Optimism Bias”, Current Biology Volume 21, Issue 23, pages R941-R945. That is where I got the quote about “one of the most consistent, prevalent, and robust biases documented in psychology” from.

The line about deadlines whooshing by is, of course, a tribute the great and often missed Douglas Adams, from The salmon of doubt: Hitchhiking the galaxy one last time. London: Macmillan, 2002.