There is an old joke which asks - how to tell if a politician is lying? The answer - if they are moving their lips.
In the midst of an election campaign a more scientific answer to this vital question may be provided by some recently published psychology research examining the prevalence of lying in the UK population.
The analysis was conducted by researchers from Oakland University in the USA and Korea University in the Republic of Korea, analysing a survey of 2,980 British Adults from The Science Museum of London, part of the museum's "Who Am I?" exhibition on human behaviour.
The survey found that men deceive more than women, people lie more to their mothers than to their partners, and most people believe there is such a thing as an acceptable fib.
The new study entitled, 'A Few Prolific Liars: Variation in the Prevalence of Lying', found that there is a distinct group in the general population, who tell five or more lies per day, and these prolific liars constitute 9.7% of the U.K. population.
For over 90% of the rest of the population lying is in fact a relatively infrequent activity. U.K. subjects reported an average of just less than two 'white lies' per day, and an average of just less than half a 'big lie' per day. Although generally infrequent, lying is still more prevalent in the United Kingdom than in the United States.
U.K. adults tend to consider deceiving a loved one as worst; lying about love, lying to a partner about who you have been with, and fibbing to a partner about where you have been, are the most frequently cited 'big' lies.
There is general agreement between prolific and everyday liars with regard to what constitutes a big lie. Exceptions were reported: Prolific liars are less likely to consider it a 'big' lie to call in sick when feeling fine.
In contrast to the once-a-week 'big lie' rate of the everyday liars, prolific liars tell almost three 'big lies' a day; this is in addition to the six white lies they tell on an average day.
The researchers, Kim Serota at Oakland University, and Timothy Levine (now at the University of Alabama at Birmingham in the USA) found prolific liars are younger, more likely to be male, have higher occupational status; are much more likely to work in business, professional and technical occupations.
Mothers are the people most likely to be lied to, and this is supported by results from everyday liars, however, only 14.9% of prolific liars cite their mother as the leading target of their fibs. Prolific liars are more likely to deceive most their partner and their children.
Occupationally, prolific liars are more likely to be found among managers and supervisors than among workers, and among management, those 55 years and older are more like to be prolific liars.
More than 70% of U.K. adults say that it is okay to lie in order to protect someone or avoid hurt feelings; however, prolific liars are less likely to be concerned about wounded spirits, and are more likely to approve lying to protect a secret.
At work, prolific liars are 4 times more likely than the rest of the population to have been reprimanded for lying and almost 9 times more likely to have been fired for their dishonest behaviour. Prolific liars are also 4 times more likely to report losing a partner because of their lying habits.
The study published in the academic journal, 'Journal of Language and Social Psychology', concludes prolific liars tell more white lies and more big lies than do the rest of us. Although the prolific to everyday liar ratio for white lies is a substantial 5.5 to 1, the ratio for big lies is an even more striking 19.1 to 1.
Kim Serota argues that over time some people become conditioned to lie more than others. That is, they spend more time in problematic situations and become more adept at lying. Therefore, while most of us default to the truth, they more easily default to lying as a learned approach.
The idea that people who face more problematic situations are more likely to choosing lying over truth does have some currency in the UK data. Kim Serota points out that we know that people generally lie less as they age.
But an exception is managers and executives, who are more likely to be prolific liars as they get older (and presumably rise in the managerial ranks). Senior managers face more difficult and costly decisions, and appear more inclined to use lying instead of truth-telling, because they have learned to be expedient.
Kim Serota concludes that people lie when the truth doesn't work. The careers of politicians are likely to mirror the careers of executives because the truth often may not work in politics.
What this research suggests is that if you want to really find out which politician in an election campaign is lying - we need to firstly more usefully reframe the question - which ones are 'prolific liars'.
Telling one or two lies is so common in everyday life as to make this an incidental finding.
So the classic journalistic pursuit of a particular lie is a waste of time and reveals nothing meaningful.
Instead it might be more helpful to detect whether a politician comes from this newly identified distinct population of 'prolific liars'.
The classic journalistic aggressive interview of the politician themselves is almost certainly useless in terms of detecting deception - they are too clever and prepared for that.
What would be more useful is to hear from the ex-girlfriends and ex-boyfriends of our candidates and their work ex-colleagues (how often did they ring in 'sick').
A televised debate between ex-spouses and lovers where character of the politician becomes the issue, might be more revealing than current broadcast arguments between politicians.
Timothy Levine argues that that politicians probably lie more than the rest of us because they have to. People lie when the truth is a problem. For most of us most of the time, reality does not make communication a problem. Politician's in contrast face situations all the time where the truth just can't be said.
We get the liars we deserve, because we just can't handle the truth.