While the media coverage of the new royal baby has been overwhelmingly positive, there are always a few spoilsports who take every opportunity to complain. Their childish diatribes generally follow a pattern as predictable as it is boring. They demonstrate how much New Zealand's monarchy has evolved in the last 60-70 years and how little republicans have changed.

The arguments used against the monarchy are quite familiar to New Zealanders. They ought to be, they're the same arguments that have been used since the 1950s.

Republicans earnestly declare that New Zealand ought to "grow up" to "cut the apron strings" and to "stop bowing and scraping to Britain". It is hard to believe that, in the early 21st century, there are still people who think New Zealand is not already a mature country, entirely free from its historical, colonial bonds.

In the last few decades, New Zealand has demonstrated to the world exactly how mature and confident it is. Our anti-apartheid efforts, our anti-nuclear stance, our peace-keeping missions and our pursuit of environmental protection are well-known across the globe. No one in the world believes that New Zealand is a vassal state of some British Imperial overlords.

Republicans cling to an outdated view of New Zealand. In many ways they have to. Only by convincing Kiwis that they are not mature, proud and independent can they advance their own agenda.

We all know that Aotearoa is a great country. This country has one of the finest constitutions in the history of the world and one of the longest traditions of unbroken democracy. New Zealand's monarchy is an important part of that constitution and democracy.

Our monarchy is especially remarkable because it is shared among 16 independent countries. Republicans decry this arrangement as strange and backward. But, in a shrinking world where globalisation and international co-operation are vital, sharing our head of state is something to be proud of. The insular and selfish values espoused by republicans are at odds with the modern world. Ironically, it is republicans with their inward-looking view who would be more comfortable in the 1950s than our own 87-year-old Queen who is much-admired in the fast-moving modern age.

In the 20th century, republicans accused those who supported the monarchy of suffering from "colonial cringe", a belief that New Zealand was inferior to Britain. In the 21st century however, the absurdity of these claims is clear for all to see. It is republicans who are unhappy, who feel New Zealand is somehow inferior and immature. They couldn't be more wrong. Kiwis have a lot to be proud of and the new royal baby is just one more reason to celebrate.

Dr Sean Palmer is chairman of Monarchy New Zealand. He has a Masters and a PhD on the importance of the monarchy to New Zealand.