“THE love of money”, St Paul memorably wrote to his protégé Timothy, “is the root of all evil.” “All” may be putting it a bit strongly, but dozens of psychological studies have indeed shown that people primed to think about money before an experiment are more likely to lie, cheat and steal during the course of that experiment.

Another well-known aphorism, ascribed to Benjamin Franklin, is “time is money”. If true, that suggests a syllogism: that the love of time is a root of evil, too. But a paper just published in Psychological Science by Francesca Gino of Harvard and Cassie Mogilner of the University of Pennsylvania suggests precisely the opposite.

Dr Gino and Dr Mogilner asked a group of volunteers to do a series of what appeared to be aptitude tests. As is often the case in such experiments, though, what the volunteers were told, and what the truth was, were rather different things.

In the first test they were asked to make, within three minutes, as many coherent sentences as they could out of a set of words they had been presented with. What they were not told was that each of them had been assigned to one of three groups. Some volunteers’ word sets were seeded with ones associated with money, such as “dollars”, “financing” and “spend”. Some were seeded with words associated with time (eg, “clock”, “hours”, “moment”). And some were seeded with neither. Thus unknowingly primed, the volunteers were ready for the second test.

This was mathematical. They were given a sheet of paper with 20 matrices which each contained 12 numbers, two of which added up to ten (for example, 3.81 and 6.19). They had to write down, on a separate answer sheet, how many of these pairs they could manage to find in five minutes. They were also given a packet of money and told they could reward themselves with a dollar for each pair they discovered.

Crucially, they were not asked to show their workings on the answer sheets—and the matrix sheets, on which those workings might have appeared, carried no identifier and were ostentatiously discarded once the test was done. Nevertheless, by hiding an identification code in a sample matrix on the answer sheet, Dr Gino and Dr Mogilner knew which matrix sheet each candidate had been given and thus who had cheated and who had not. They found that 88% of those who had been primed with money-related words in the first test cheated, as did 67% of those given neutral words. Of those primed with time-related words, though, only 42% cheated.

Nor, despite St Paul’s aphorism, was the lure of lucre during the experiment (as opposed to the effect of thinking about it as a result of being primed) necessary as a corrupting influence. A similar trial on different participants showed that presenting the matrix as a test of intelligence also caused those primed with the idea of money to cheat more than those primed with the idea of time—though, intriguingly, that did not apply if the matrix was presented as a test of personality.

This led Dr Gino and Dr Mogilner to suspect that self-reflection played a part in controlling unethical behaviour during the test. They therefore conducted a third test in which, for half the volunteers, there was a mirror in the cubicle they were sitting in when doing the experiment.

Volunteers primed to think about money cheated 39% of the time when a mirror was present but 67% when it was not. Those primed to think about time cheated 32% of the time in the presence of the mirror and 36% in its absence—results that are statistically indistinguishable.

Finally, a fourth experiment asked primed volunteers to fill in a questionnaire before tackling the matrix. In among “filler” questions intended to disguise what was happening this asked them to rate how they felt about self-reflective statements like, “Right now, I am thinking about who I am as a person.”

As in the previous tests, those primed with money words cheated more often than those primed with neutral words and far more often than those primed with time words. But whether someone cheated was also related to how strongly he felt about the self-reflective statements presented to him in the questionnaire.

It seems, then, that thinking about time has the opposite effect on people from thinking about money. It makes them more honest than normal, rather than less so. Moreover, the more reflective they are, the more honest they become. There must be an aphorism in that.