Neuroscience
From a host preparing for a dinner party to a country constructing a new national stadium, we all tend to underestimate how long things are going to take - an error that's been dubbed the 'planning fallacy'. According to Ola Svenson, contributing to this proclivity for tardiness is our inability to accurately decide between time-saving options.
Consider these increases in speed for a 100km car journey. Don't work out the detailed mathematics. Rather, for both pairs, just make an intuitive judgement about which jump in speed will make the largest difference to your time of arrival (i.e. save the most time):
It can also apply in other contexts. Consider an administration overhaul at a hospital clinic, such that the number of patients treated by each doctor per day is increased. In each pair, which improvement would free up the most doctors to go and work elsewhere?
So why do we always apply the Ratio Rule if it consistently leads to the wrong judgement? Svenson said the Ratio Rule works when both options start from the same point (e.g. the same speed, or the same number of patients treated). This may then lead it to become a reinforced and favoured rule applied in real-life experiences.
According to Svenson, this bias in the way we compare time saving options has real-world implications. For example, people who are already driving fast will overestimate the time saved by driving even faster. Meanwhile, politicians may be prone to improving an already fast operation, rather than making improvements to a slower operation with more time-saving potential.
_________________________________
SVENSON, O. (2008). Decisions among time saving options: When intuition is strong and wrong. Acta Psychologica, 127(2), 501-509. DOI: 10.1016/j.actpsy.2007.09.003
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
- Driver Stereotypes Affect Our Memory Of How Fast A Car Was Travelling
When I see a car fast approaching in the rear-view mirror, I find I can't help but make assumptions about the personality of the driver based on the model of car they're driving. Now a new study suggests these kinds of stereotypes can affect our...
- Our Bodies Fail To Adjust To Seasonal Clock Changes
The UK and other countries have been altering their clocks with the seasons since at least the beginning of the last century. The argument in favour of Daylight Saving Time (DST), or British Summer Time as it's called in the UK, is clear: daylight...
- Pick A Doctor, Any Doctor
Some countries are worried that so many of their doctors are coming to work in the UK. Now Adrian Furnham and colleagues have highlighted another concern regarding the NHS’ increasing dependence on foreign doctors. They report that white British people...
- Is It Really True That Therapists Don't Improve With Experience?
When choosing a therapist, you’d be forgiven for wanting someone with plenty of experience. But then you might well be unaware of all the studies that, to psychotherapy’s embarrassment, have failed to find any association between therapist experience...
- Neuropsychology Abstract Of The Day: "cognitive And Behavioural Predictors Of Survival In Alzheimer Disease"
Cognitive and behavioural predictors of survival in Alzheimer disease: Results from a sample of treated patients in a tertiary-referral memory clinic Int J Geriatr Psychiatry. 2011 Sep 29; Russ TC, Batty GD, Starr JM Abstract OBJECTIVE: This study examined...
Neuroscience
We're useless at choosing between time-saving options
From a host preparing for a dinner party to a country constructing a new national stadium, we all tend to underestimate how long things are going to take - an error that's been dubbed the 'planning fallacy'. According to Ola Svenson, contributing to this proclivity for tardiness is our inability to accurately decide between time-saving options.Consider these increases in speed for a 100km car journey. Don't work out the detailed mathematics. Rather, for both pairs, just make an intuitive judgement about which jump in speed will make the largest difference to your time of arrival (i.e. save the most time):
a)Travelling at 50km/h instead of 40km/h.If you're like most of the participants in Svenson's study, you will have assumed that option (b) in both pairs is the most time saving. In fact, for the first pair, the time saved is equal (allowing for rounding off), and for the second pair, option (a) saves more time. From analysing participants' judgements, Svenson found that people seem to be mistakenly comparing the ratios of the two changes in speeds - applying what she calls the Ratio Rule.
b)Travelling at 130km/h instead of 80km/h.
a)Travelling at 50km/h instead of 30km/h.
b)Travelling at 130km/h instead of 60km/h.
It can also apply in other contexts. Consider an administration overhaul at a hospital clinic, such that the number of patients treated by each doctor per day is increased. In each pair, which improvement would free up the most doctors to go and work elsewhere?
a)Each day 11 patients treated per doctor instead of 5.Svenson again found that her participants consistently applied the Ratio Rule, so that most of them said erroneously that option (a) was more time saving for the first pair, and that option (b) was more time saving for the second pair.
b)Each day, 8 patients treated per doctor instead of 4.
a)Each day, 8 patients treated per doctor instead of 4.
b)Each day, 16 patients treated per doctor instead of 7.
So why do we always apply the Ratio Rule if it consistently leads to the wrong judgement? Svenson said the Ratio Rule works when both options start from the same point (e.g. the same speed, or the same number of patients treated). This may then lead it to become a reinforced and favoured rule applied in real-life experiences.
According to Svenson, this bias in the way we compare time saving options has real-world implications. For example, people who are already driving fast will overestimate the time saved by driving even faster. Meanwhile, politicians may be prone to improving an already fast operation, rather than making improvements to a slower operation with more time-saving potential.
_________________________________
SVENSON, O. (2008). Decisions among time saving options: When intuition is strong and wrong. Acta Psychologica, 127(2), 501-509. DOI: 10.1016/j.actpsy.2007.09.003
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
- Driver Stereotypes Affect Our Memory Of How Fast A Car Was Travelling
When I see a car fast approaching in the rear-view mirror, I find I can't help but make assumptions about the personality of the driver based on the model of car they're driving. Now a new study suggests these kinds of stereotypes can affect our...
- Our Bodies Fail To Adjust To Seasonal Clock Changes
The UK and other countries have been altering their clocks with the seasons since at least the beginning of the last century. The argument in favour of Daylight Saving Time (DST), or British Summer Time as it's called in the UK, is clear: daylight...
- Pick A Doctor, Any Doctor
Some countries are worried that so many of their doctors are coming to work in the UK. Now Adrian Furnham and colleagues have highlighted another concern regarding the NHS’ increasing dependence on foreign doctors. They report that white British people...
- Is It Really True That Therapists Don't Improve With Experience?
When choosing a therapist, you’d be forgiven for wanting someone with plenty of experience. But then you might well be unaware of all the studies that, to psychotherapy’s embarrassment, have failed to find any association between therapist experience...
- Neuropsychology Abstract Of The Day: "cognitive And Behavioural Predictors Of Survival In Alzheimer Disease"
Cognitive and behavioural predictors of survival in Alzheimer disease: Results from a sample of treated patients in a tertiary-referral memory clinic Int J Geriatr Psychiatry. 2011 Sep 29; Russ TC, Batty GD, Starr JM Abstract OBJECTIVE: This study examined...