But they did. They used a lot of different indication for where islands were - bird migration, ocean currents, etc.

They had already come a very, very long was from Asia to Australia, Fiji, Tonga, Samoa, French Polynesia, Hawaii, etc. Finding land in an impossibly vast ocean was kind of their jam.

Hitting the population limit of your island, and strong cultural norms around exploration.

If you see birds come from that direction, or tides come from that direction with flotsam, then you can bet there is land. Within certain range, if you see specific clouds or tones on the horizon, you can also imply land. Also, if you head that way the Americas are kind of hard to miss.

How do we know they didn't know they would find anything? There is lots of evidence that we have lost perspectives on how to analyse our environment as we have gained new ones through technology.

I think the article alludes to it. First sons world inherit everything so little brother would have to sail out to find new land.

You could say that about almost any explorer ever.

But modern explorers don't expect death if the "nothing" situation comes to pass. These were people that staked their life.

They brought food, they captured water from rain and condensation, and they could fish. Yes it was risky but they had a lot of runway due to their expertise on the water.

Modern explorers also can be reasonably assured there will be enough food to go around next year or the year after if they stay home.

Well modern explorers have the benefit of always knowing that there is a "something", but probably still understand that there is risk in what they are doing. Historically though, plenty of explorers from many different cultures travelled to where there was potentially "nothing". Why would Pacific Island cultures be any different?

Curiosity is a very powerful thing.

Testosterone.

Men and women travelled on the canoes together. Colonisation of islands is difficult if you only have guys eh?

Certainly oral legend of the Māori is mixed crews e.g. “According to some accounts, Horouta was the first waka [=canoe] to make landfall in this region. The captain of the Horouta was Pawa, the navigator was Kiwa. It carried a large crew of men, women and children – as well as a dog named Whakao, belonging to Pawa.”

Having women and children on board isn't necessarily incompatible with the idea that the drive for the insanely risky exploration was fueled by testosterone.

So these days with so many artificial ingredients and ultra processed foods and sedentary habits leading to decreased testosterone these journeys might not have taken place had they had our modern diets [and as child comment adds, lifestyle]?

I'm far from a scientist, but in my observations and reading, lifestyle has a far bigger impact than diet. Hard work boosts testosterone, there was even a study done showing how much it was boosted during chopping wood, for example. Modern folks are sedentary and often overweight, both of which contribute to lower testosterone, likely moreso than diet ever could.

Men today are observably less 'manly' than in the past. But we seem to try to find someone or something to blame other than ourselves.

It seems that phthalates (plastic softeners) are also reducing testosterone.

https://doi.org/10.1093/humrep/dev225

A bit of A, a bit of B.

The modern diet is also very processed and refined. White bread and white rice were not available for mass consumption until industrialization.

Japan's navy solved an issue with beriberi disease after changing the rations from white rice to barley. https://www.atlasobscura.com/articles/rice-disease-mystery-e...

Maybe also selection pressure (which has largely been removed). The men _who_survived_ were more manly in the past.

Perhaps, but I think we can drill down a bit further.

Many third world countries have foods much, much more processed than we do in USA, yet they don't exhibit such effects generally.

My own family is a huge old Irish/German conglomeration...I have 12 uncles and aunts. There's very clear demarcation of millenials vs the older ones, and especially those raised in a rural setting vs urban.

I'd honestly like to see studies of how many, let's say 'metro' men spent summers bucking hay or stripping tobacco as a kid. I did, but I'm clearly less grizzled than my cousins who did such work year round as a kid.

And I don't mean any of this to be insulting. I'm way less manly than my own father, and a millennial who spent childhood glued to screens.

Why do you describe something like bucking hay or stripling tabacco as 'manly' when it was a common activity for women as well in traditional society?

I don't. I just mentioned them because they are very common labor intensive summer jobs where I grew up. Replace with whatever your local variant would be.

Problem is that unless you've actually got symptoms of low testosterone, it's not a big issue. Low T being the cause of men's problems today is a myth.