What are the odds that an Intelligent alien race would be humanoid?

I look at it from another way. Humans are the sum of all the failed life before us. It seems to me that to actually survive the eons necessary to become technologically and culturally advanced, you'd need some key human features.

Life would have to form under conditions far different then our own for some kind of insectoid or reptile man to be the peak of sapient evolution. I think we humans evolved the way we did because of the challenges of the environment. We're the only species that has evolved to be a blank slate capable of changing or adapting to nearly any environment, while the others are completely dependent on an ideal environment they were designed for. Take that away and they go extinct quickly.

In a nutshell, hands with opposable thumbs = good, Claws = bad.

Alien Humanoids

Personally I think the odds are good, better than 50/50

Reasons

Complex life will almost certainly be multicellular, and to evolve bigger than a few millimeters long they will need a gut to absorb food, that means they will have a mouth at one end and a rectum at the other.

This gives them a front and back (mouth is the front so they move towards food) so their sense organs (smell taste eyes ears) will cluster round the mouth to recognise food, so they will have a face of sorts.

The signals from these sensors will have to be processed so they will need a brain and it will be close to the eyes to keep the signal path short, so they will have a head.

Unless they live in the sea (unlikely as they will need to use fire for technology) they will have legs, Four is the most efficient number although six is possible. and to become advanced their front legs will need some sort of graspers (hands)

so they will probably finish up looking a bit like us in general form.

Here's a thought, if the dinosaurs had not been wiped out 65 million years ago they might have evolved into intelligent humanoids, T Rex had already learned to stand on two legs

Cheers, Alan

No. The odds are against extraterrestrial life being humanoid. They might walk upright, or might not. They might roll instead of walk. They might have bilateral symmetry, or trilateral symmetry, or some higher multilateral symmetry, or radial symmetry, or no particular symmetry. They might have two sexes, but they might have more than two. They might vaguely resemble some terrestrial life form, but they might not. Their metabolism might use some of the same chemicals that ours does for energy, but they might use other ones instead. The safest thing to predict is that they will be competitive, and probably aggressive, since the evolution of life should everywhere favor those qualities above the sentimental "virtues" that human religions usually favor.

Humans have not been around long enough to have earned the right to brag. Our recent successes, as measured by technology and by population growth, seem likely to go bust and backfire on us. We've come to rely on fossil fuels, which have gone into decline, and the decline will become more rapid in coming years. When fossil fuels have become depleted, humans won't have the means to maintain their population, so there's a large die-off event in the near future for mankind. Perhaps 90% of our population worldwide will die of starvation, disease, or violence.

Technology consumes fossil fuels. When fossil fuels are depleted, there will be no more electricity, at least where most people are concerned, to operate electrical appliances and power tools. That means most people will have to go back to hand-tools, and that most human labor will need to be devoted to agriculture.

Anybody can grow flowers in a square-meter bed. When I was younger, I farmed a quarter acre garden, growing a variety of vegetables, and became familiar with how much backbreaking work is involved in farming even a small bit of land without chemically powered tools. I could not do it today.

But that's the kind of work that everybody will have to do when fossil fuels are gone. And matters will be made more severe by the fact that other humans will follow a predatory strategy to get their own sustenance, and this will require the diversion of some human labor to defense and to exacting vengeance upon the food thieves.

All we've done to this point does not mean that we will ultimately gain the survival longevity of the dinosaurs, much less that of the insects. If we become extinct as the result of our unwise reliance on fossil fuels and by our failure to establish the correct hierarchy of privileged use of exosomatic energy, then humans will have been nothing more than a very conceited flash in the proverbial pan.

The difficulties finding a planet with Earth's physical compounds on the ground and troposphere aside, it would be very difficult finding a planet the right distance from its star and that has the gravity needed to have humanoid life. You would most likely need comparable day lengths and gravity to develop as a humanoid species. I would think you would also need comparable ground densities.

I never understood why they portrayed aliens as little green men until, I read they were really seen that way, abductions,...I don't think some look that way, of course, that could be one race of species. Some could be more animal or creature like, lots of different kinds . There could be a planet just like ours, maybe, the people there look the same as us. Gotta ask how they fly those UFOs, though & are technologically advanced.

They could look pretty bazaar in color and configuration but they would likely be humanoid and roughly our size and likely parallel us closely in intelligence.

I think you mean hominid. I'm not sure where you come to the conclusion of 'highly unlikely'. Intelligent creatures would need to be land-dwelling. They would need to be bipedal. They would need to develop a spoken and written vocabulary. They would need to master nature and use tools.

This pretty much narrows it down. Any creatures which were to be worthy of communication would be similar to ourselves.