"Sunlight is the best disinfectant." If this cliché is right, we should welcome the publicity being given to allegations of MPs' sexual harassment as a means of cleaning up politics. After all, if an MP can abuse his power in one domain*, in what other ways might he do so?

I fear, however, that things aren't so simple.

A recent experiment (pdf) by Andreas Ostermaier and Matthias Uhl shows one problem. They got people to roll a die and report the result, being paid for high numbers. They found that some people - those with consequentialist rather than rule-based moral codes - were less dishonest if they had to report in public than in private. This suggests sunlight is the best disinfectant.

But, but, but. Their public declarations were not wholly truthful. Instead, they lied by exactly as much as they expected others to lie; they preferred to be seen as crooks than mugs.

This experiment tells us something important. Scrutiny encourages not so much ethical behaviour as conformity to norms. Which poses the problem: what if these norms are themselves unethical? As Ostermaier and Uhl say:

As public scrutiny reinforces conformity with empirical expectations, it can promote unethical as much as ethical behaviour

We don't need to look far for external validity here. In last year's presidential election, Democrats hoped that revelations about Trump's bad behaviour would lose him support. In fact the opposite happened. Democrats misjudged the norms held by many voters, who saw pussy-grabbing as evidence that Trump rejected the "political correctness" they hated and dishonest business deals as evidence that Trump could deal well on the US's behalf. The norms for decent honest behaviour weren't as strong as Democrats thought.

Another example comes from former Communist countries. Rigorous scrutiny of people's political views led them not to espouse ethical views, or even their own private ones, but rather support for dictators - something which helped sustain oppressive regimes because everybody believed that everybody else supported them. Timur Kuran calls this preference falsification.

I fear something similar might apply in the case of "sex pest" MPs. Professional golf-club bigots - you know who they are - respond to the allegations by blaming victims, "political correctness" and humourless feminazis zzzzzzz. In this way, the danger is that there'll be a backlash against feminism rather than that bad behaviour will be weeded out.

Where norms are weak, publicity doesn't drive out bad behaviour and might even encourage it.

In fact, I have another, different, concern. Remember the MPs' expenses affair. This contributed to naïve cynicism - "they're all in it for themselves" and suchlike dazzlingly original "thoughts" - and a loss of confidence in political representatives**. The upshot was a (further?) decline in the idea of politics as a rational deliberation about the public good in favour of a narcissistic pressing of one's own views, howsoever ill-thought out.

It mightn't be wholly fanciful to see a link between the MPs' expenses affair and the EU referendum; the former fuelled the belief that MPs were not fit to take decisions on our behalf.

I fear that revelations about MPs' sexual misconduct might have the same effect. Is it really an accident that the sexual harassment spreadsheet has been publicised by a sort-of-libertarian who despises the conventional political process?

I say all this in sorrow. And I do so not merely (or even mainly) to make a point about sexual harassment. My point is that the social sciences are a matter of identifying mechanisms. There are several potential mechanisms at work here. And the one that leads to MPs' behaviour improving is, I fear, only one possible one.

* I'm assuming, arguendo, that there's some truth in allegations of genuinely oppressive behaviour rather than just "high jinks", misunderstandings and gaucheness.

** I suspect there was a massive dollop of hypocrisy over the affair. Many of the angry older white men who professed to be outraged by MPs' expenses claims are themselves not wholly unacquainted with imaginative accounting. Perhaps the same could be said of sexual harassment allegations.