It's just three paragraphs. MPs are advised they can't claim the cost of buying, cleaning and maintaining clothes and shoes on their tax, just like most normal people.

But it's the next two pars that catch the eye if you're aware of research about why so many relatively rich and powerful people are caught doing questionable things.

The ATO provides a helpful example of the kind of pollie clothing claim it will refuse.

"A Member decides, as a result of the televising of parliamentary proceedings, to purchase a range of high quality garments to wear on those occasions. A deduction is not allowable because there is an insufficient connection between the acquisition of these items and the Member's work-related activities," the ATO said.

Those two sentences have the leaden feel of having been said, written, explained and argued by too many pollies, too many times.

You can imagine an agitated federal pollie, struggling to make ends meet on a base salary of $207,000, exhorting his or her accountant to make the case he or she ONLY wears the new $3000 outfit in bright hues in parliament so constituents can EASILY SEE their hard-working local MP during televised debates.

"So it HAS to be a work-related expense, Gerald, plus I wouldn't be seen DEAD in anything but Armani/Gucci/McQueen/Choo in my own time," I imagine the cranky pollie saying to an accountant who's adopted the long-suffering look of a person dealing with twin atrocities - maths on a daily basis and excessive exposure to the emotionally stunted.

We've been talking about Newstart this week, the push by many - including former prime minister John Howard - to significantly increase it from $277 per week for singles, Prime Minister Scott Morrison's responses to the suggestion, and a federal Minister's blocking of a parliamentary inquiry's support for unemployment benefits to rise for the first time since the 1990s.

Mr Morrison isn't a fan of increasing a benefit that's considerably below the poverty line. He's sticking to the line that 99 per cent of people on Newstart are also on other government benefits, despite media highlighting many of that 99 per cent only receive an energy supplement of $4.40 per week as their "other government benefit".

Even the big ticket "other government benefits" should be put in perspective. Single Newstart recipients renting privately are entitled to up to $137.20 each fortnight, but their rent must be more than $305 per fortnight.

And about 9 per cent of Newstart recipients also receive the family tax benefit of $200 per week, but that's to support children.

Federal politicians almost choke in the rush to assure a sullen public they're not responsible for setting their own pay. It's the Remuneration Tribunal's fault, apparently. But it was pollies who set up a system requiring annual reviews, that just gave MPs a 2 per cent increase only months after some of the lowest-paid workers in the country gained 3 per cent from the Fair Work Commission.

It takes a couple of key strokes to find all the extra benefits and allowances available to federal politicians, including a $288 daily allowance when parliament is sitting, expense or entertainment allowance, a committee allowance, postage, printing, stationery and telephone allowances, travel allowance and a $19,500 per year vehicle allowance, not to mention life gold and severance passes.

Independent Andrew Wilkie and former Senator Derryn Hinch described one parliamentary perk, the electorate allowance of between $32,000 and $46,000, as a scandal that was open to abuse and misuse because it relies on, ahem, an honour system. Politicians receive the allowance into their accounts each month and return any unspent funds at the end of the year. No problems there, hey what?

University of California researcher Paul Piff has done more than most to show the rich are different, but his best work has shown you don't even have to be very rich to be an arrogant, out-of-touch, empathy-free, greed-fuelled, narcissistic tosser - you just have to think you're better off or more powerful than others to, literally, take candy from a baby.

In one study participants were told a jar with individually wrapped candies was intended for children in a nearby laboratory, but they were free to have some. The better off people were, the more they took.

Piff's studies over the past few years - reported in journals and the World Economic Forum - have led him to conclude that "higher social class predicts increased unethical behaviour" and "upper class individuals behave more unethically than lower-class individuals".

Obviously there are exceptions, but his studies have consistently shown that, given the chance, the higher you are up the food chain, the more likely you are to justify looking after yourself over others.

"There is something about wealth that gives rise to a sense of entitlement, a sense that one deserves more good things in life than others, which in turn gives rise to an increased or inflated sense of self-importance," Piff said.

Politicians have argued $200,000 a year or more is not wealthy, but it's influential if you're in a position where you're dealing with people on much less, Piff has shown.

"Greater resources, freedom and independence from others among the upper class give rise to self-focused social-cognitive tendencies, which we predict will facilitate unethical behaviour," he said.

Pollies argue "If you pay peanuts you get monkeys" when it comes to their pay. But I prefer Piff's view. Some pollies will justify taking candy from babies.