Why do many people think aliens must be humanoid?

Have you ever wondered what they would be like if we actually encountered aliens one day? Would they have a human-like body structure or would they be a completely different biological form from us, such as having tentacles, wings, tails, and other features?

The human form is the best choice for intelligent life

First of all, we must make a clear premise, that what we call aliens are only highly intelligent and civilized life forms, not some microorganisms or low-level animals and plants.

Because if we only consider the existence of life, the form of extraterrestrial life can be very diverse, even beyond our imagination. But if we want to consider the development of intelligence and civilization, the form of life cannot be too arbitrary but must meet some basic conditions.

For example, intelligent life requires relatively large brain capacity to store and process large amounts of information. Intelligent life also requires a certain degree of flexibility and coordination to adapt to a variety of complex environments and challenges.

 Aliens are highly intelligent and civilized life forms. (Illustration: ZME).

Intelligent life also needs some organs that can operate tools and transmit information such as hands, eyes, mouth, etc. These conditions have been proven on Earth and humans are the most successful example.

The reason humans are the strongest species on Earth is because we have these advantages.

These advantages did not arise by chance, but were formed after hundreds of millions of years of natural selection and evolution. In other words, on Earth, the human form has proven to be the best choice for intelligent life. So could similar situations occur on other planets?

The human form has proven to be the best choice for intelligent life. (Illustration: ZME).

Convergent evolution allows for humanoid aliens

In fact, humans are not the only ones on Earth who have an evolutionary advantage. For example, aquatic animals such as dolphins, whales, and sharks have streamlined bodies adapted to move through water. Land-dwelling carnivores such as tigers, lions, and leopards have sharp teeth and claws to hunt their prey. Flying animals such as bats, birds, and insects have wings and feathers to fly through the air.

Even though these species are far apart on the evolutionary tree, they still have similar shapes and characteristics, this is called convergent evolution.

Convergent evolution means that in similar environments and pressures, different species will independently develop similar solutions to their survival needs. In other words, the human form is not the only intelligent life form on Earth, but rather it is just one more viable solution.

So, if Earth-like environments and pressures were placed on other planets, would the same evolutionary solutions as on Earth also arise? The answer is very possible.

According to some astronomers, the universe has many super-Earths. (Illustration: Zhihu).

Because the laws of physics and chemistry in the universe are roughly consistent, it follows that the basic composition and functioning of life on other planets must also be roughly similar.

Furthermore, according to the observations and speculations of some astronomers, there are many Earth-like planets in the universe, called "Super-Earths". These planets have similar sizes, masses, temperatures, atmospheres, humidity and other conditions to Earth, in other words, they have similar environments and pressures to Earth.

Therefore, if life exists on these planets, it is very likely that they will also undergo convergent evolution, evolving into forms and characteristics that are similar to those on Earth. In other words, if intelligent life exists on these planets, it is very likely that they will also evolve into humanoid forms similar to humans.

(Illustration: NPR).

Human psychology makes us more accepting of humanoid aliens

Finally, we must mention a more important reason, which is human psychology . Because aliens for us at the present time are not real living beings that exist in the universe but characters created in our imagination.

The characters we create in our imagination do not necessarily have to follow logic and scientific laws, but rather, they must fit our own psychology and emotions.

For example, in science fiction movies or novels, aliens are often the object of conflict or cooperation with humans. If the aliens are too strange or scary, it will be difficult for the audience or reader to sympathize or accept them.

But if the alien is too cute or beautiful, it will be difficult for the audience or reader to feel scared and skeptical. And if the alien is too monotonous or boring, it will be difficult for the audience or reader to feel interested or curious.

Therefore, in science fiction movies or novels, aliens are often designed to have a certain degree of similarity and difference with humans. This can not only make the audience or readers feel close and familiar, but also make them feel surprised and new. Therefore, the human form is the best choice that can balance the similarities and differences.

Image of aliens in a science fiction movie. (Illustration: NPR).

In addition, the human form can not only make us feel that aliens are intelligent, emotional and have personality, but also can make us feel that aliens are very mysterious , have special abilities and have different cultures.

Moreover, the human form also helps us easily assign many different roles and plots to aliens such as enemies, friends, lovers, leaders, etc., thereby increasing the tension and appeal of the story.

So, in movies or science fiction novels, aliens often take on human form, which is actually largely a figment of our imagination.