There's a trade-off between skill and moral behaviour, according to new research.

Armin Falk and colleagues got people to sit a form of IQ test, except that some subjects were explicitly told it was an IQ test whereas others were told it was just a questionnaire. Some were then told that for each question they got right, the probability would increase of a mouse being gassed to death. They found that the subjects sitting the IQ test were more likely to answer questions correctly - at the possible expense of the mouse's life - than those only filling in the questionnaire. They conclude:

Striving for pleasures of skill can have negative moral consequences and causally reduce moral values.

This is not the only paper to establish a link between technical skills and bad behaviour. Francesca Gino and Dan Ariely have found that creative people tend to be more (pdf) dishonest than others.

There is, I fear, no lack of external validity here. To take a few diverse examples:

- Scientists sometimes work on projects with potentially dangerous effects, such as enhancing viruses. Falk quotes Sir Mark Oliphant, a member of the Manhattan Project: "if the work's exciting, they'll work on anything."

- Soldiers can fight well even if a war is unjust.

- Civil servants can work diligently to implement policies we might find repellent (though it's questionable how often this is happening at the DWP).

- Bank traders rarely worry that their work might be socially useless.

- Accountants and lawyers can be untroubled by - or even take pleasure in - devising tax-dodging wheezes.

- Even the best footballers, as well as Diego Costa, sometimes dive.

Readers might object that I fall into this category. If I do well in my day job - a matter which I leave others to judge - the best that happens is that already-wealthy people get even richer. I honestly confess to being untroubled by this.

Herein, though, lies a paradox. All this seems to imply that societies with large numbers of skilled workers will have lower ethical standards than others. But this is not the case. There's little evidence that wealthier nations, which have higher human capital, are in aggregate less moral than poor ones. In fact, I strongly suspect the opposite: richer nations are more tolerant and less crime-ridden than poorer ones. I'd rather walk through the streets of Zurich at night than those of Lagos. This tells us that some other mechanisms offset the tendency for skills to diminish moral conduct. Ben Friedman and Deirdre McCloskey have described these.