Way back at the end of 2009, when then Act leader Rodney Hide was in trouble for using his travel perks, the Prime Minister explained that Parliament was chock-full of Type A personalities.
"Everyone thinks they make the biggest contribution to Parliament, that's just the way it is," John Key said.
Alpha types are rather fond of themselves, skilled at self-promotion, competitive and believe they single-handedly are changing the world - but their excesses sometimes get them into trouble.
The alpha syndrome seems to apply particularly to those from Northland. It may just be coincidence or the sub-tropical heat, but there is a striking number of Northlanders in the roll-call of politicians who have found themselves in trouble.
National's John Carter pretended to be a poor Maori called Hone on talkback, Labour's Dover Samuels got himself into trouble and then out of it and has since fostered a reputation as the champion for others already in trouble or those who are trouble waiting to happen - such as Bill Liu, the Chinese man that Shane Jones awarded citizenship to, for which he is now being investigated by the Auditor- General.
National's Phil Heatley broke the rules for his work credit card to buy a bottle of wine and take his family on holiday. Shane Jones, Hone Harawira, and Winston Peters all have found themselves in political strife with the button stuck on repeat play.
John Banks harked from Whangarei and is currently sampling his own spot of bother over donations from Kim Dotcom and Sky City. Even Rodney-based Speaker Lockwood Smith might now be a venerable figure, but there were his comments about small Asian hands making light work of fruit picking before the 2008 election.
Add them all together and the gallery of Northlanders at various stages of reform is large compared to other regions. But they are by and large entertaining and eloquent, which goes a long way to explaining their longevity in politics.
Most of the alpha-extreme MPs can offer a colourful quote, always a powerful weapon on the right issues. Shane Jones this week dismissed the Green Party's opposition to mining, saying they cared more about the brown spotted kiwi than the brown kiwis heading for Australia - jobless Maori.
Hone Harawira's style is more blunt but no less effective. This week he suggested the Maori Party could not accuse National of being a thief while it continued to live from the proceeds of its crimes. It was a chihuahua yapping at its master but happy to return to the kennel for a feed.
Alphas will probably prefer their more exciting, if uncertain, lives to those at the other end of the spectrum, such as Labour's band of merry vest wearers.
A horrified Jacinda Ardern tweeted a photo of leader David Shearer, deputy leader Grant Robertson and MP Iain Lees-Galloway in matching sleeveless vests and shirts.
In the United States this year, Rick Santorum made very similar vests a trademark of his run for the Republican presidential nomination. He also made US$300,000 for his campaign funds by selling branded vests to donors.
He wore one at a campaign event in Iowa and finished just eight votes behind his rival Mitt Romney in the state. After the result he said, "the vest gave me this power".
The vest gave him recognition - something Shearer could do with. It was a bonus for Bemidji Woolen Mills, a small family company whose owner described Santorum's vests as "like a gift from God".
Nonetheless, the vest wasn't enough to get Santorum over the line - he withdrew from the race in April.
Over here, David Shearer is unlikely to ever wear one again. He is averse to gimmicks, especially ones that make him look just a little bit fuddy duddy.
His preferred image is that served up to the nation when the former aid worker entered politics - footage of himself striding through war zones wearing a bullet-proof vest.
That is suspiciously alpha so Shearer might like to learn a lesson from the Northland alphas - his holiday home is at an idyllic bay in Northland, somewhere between Dover Samuels' idyllic Matauri Bay and Winston Peters' idyllic Whananaki home base. It may pay for him not to spend too much time there.