Let's say we have cyborgs. They have human minds(mapped into software), but no human body parts and create no hormones. How would this affect their behavior, life and quality of life?

  • $\begingroup$ Im not sure what the others think about this but in my opinion it doesnt make much sense. Hormones regulate our development and functions. If you replace all that with software you cant have an human brain, as one wont exist without the others you would have to rebuild the brain to use software as control and regulation which will make it not human anymore... $\endgroup$ Mar 17, 2016 at 13:57

4 Answers 4


Dead. Or at least very broken

The human brain requires hormones to operate. For example:

Hormones secreted by the adrenals, gonads and thyroid play an important role in mediating how the environment shapes the structure and function of the brain during early development, adult life and senescence.

If you were to engage heavily in genetic engineering, you may be able to create a H. sapiens derivative which needs no hormones, but thats a very different question.


From a small bit of research, I found that hormones act on different bodily functions and process such as:

  • Development and growth
  • Metabolism of food items
  • Sexual function and reproductive growth and health
  • Cognitive function and mood
  • Maintenance of body temperature and thirst

While several of these don't apply to your cyborg situation, I would imagine that the cognitive function and mood still would. This is of course assuming that when you say they have a human mind you mean a physical, functioning human brain.

Some more digging has revealed that women who have hormone therapy midlife have lower risk of dementia, and men with high levels of testosterone have better visual and verbal memories. These are based on studies which of course do not display causation, but merely a relationship between hormones and other cognitive functions.

So for your cyborgs, it may actually be more likely to get something like dementia or they may have a faster decline in mental abilities overall.

To speak to Cort Ammon's answer, it is mentioned that the brain is shaped and structured by hormones while in the different phases of life. However, this may not affect your cyborgs as I'm assuming they have a fully developed brain transplanted in them that no longer needs hormonal influence, if that makes sense scientifically.


Since the brain isn't available in an easily readable computer format, I think your 'upload' will already take care of most of the solution.

Basic brain anatomy, biology, and evolution

When talking about 'uploading a mind to a computer', people tend to think of uploading the conscious mind only. However, due to how the brain is constructed, it's pretty much impossible to isolate the conscious part only (mainly because there is no such part visible in the biology...).

All the examples and basic understanding are taken from John Eccles' book on the Evolution of the Brain, by the way.

Anatomically, a brain is a huge neural net (or, more correctly: neural nets have been created to imitate a brain's function...) where you can't just cut out a part you need and then expect it to function perfectly. Neural nets are more or less blackboxes that you feed with input, have a look at the output, and the output generates feedback that goes back into the box to edit the way the neurons make their decisions. That way, the next time you input the exact same stuff, you might get the same result again, but you also might get a wildly different one (or anything in between).

This malleability is used to make the neural net learn. And pretty much every neural node inside this network is necessary, because it is part of the constant processing-feedback-improving machinery.

Evolution-wise, there was a small lizard-like brain, first. It took care of the things a basic animal needs to live (and I am talking about pre-vertebrate basic here), including all sensory processing etc. Then there came a secondary shell with some higher functions afterwards, vertebrate level. It didn't replace the lower shell, or extend it, but just slapped on its higher functions like improved visual tracking/recognition without ever replacing the lower ones. Kind of like an icecream cone -- the top one is the most accessible for eating, but the lower one is still there and lickable. And then evolution decided on a third shell (mammals), the major part of our brains, and once again it was just slapped on top of the already-existing mess.

Visiual processing, for example, takes place on many levels, so even people who are completely blind due to problems with the visual cortex can react unconsciously to visual stimulus because some very basic things are being processed in lower brain levels.

Biologically, the brain uses highly inefficient ways of triggering the neurons -- it doesn't use copper wires to transmit electrical impulses (300,000 km/s) but a chemical transport channel facsimile that can transport signals at 50-1000 meters per second. Additionally, even if the signal gets transported to its target neuron, the neuron itself only gets activated in about 30% of the cases. Not to mention that due to it being a chemical process, there's a limit on how often the neuron can be activated in a certain period of time before it becomes unresponsive.

The Cyborg Brain

Basically, if you want to transfer a mind to a cyborg (and then still be able to recognize the mind as the person they were before), you need to model the entire brain including all the evolutionary waste, the ineffecient way of activating neurons, and the terrible redundancies.

So, during the upload you get the unconscious part, too. And that includes the cerebellum (the earliest lizard-part of the brain that was there first during evolution) -- the part that contains control for most of the hormonal glands (directly or indirectly). You get quite pretty locations where the brain presses the button 'please release hormone XYZ', and an intelligent cyborg design will then provide a virtual hormonal gland that simulates the effect.

But why keep a virtual hormonal gland at all?

well, for one, hormones like adrenaline help the person react in dangerous situations. If the brain was jacked up like this all the time, it would lead to stupid decisions, but in emergency situations? Do it! Your cyborg probably already has such an... overclocking function, so why not link it to the adrenal gland trigger, too?

Serotonin, oxytocine and dopamine create feelings of reward/nice/fun/feel-good. They are part of the body's huge punishment-reward system that makes sure the animal takes care of its survival. Or they make sure that you seek out social contact (oxytocine), which once again gives you a better chance of survival. If you deactivate all those mechanisms for your cyborg, you will get lone wolf psychopathic ascets that might also be suicidal rambos. You probably won't get a functioning human out of it.

It isn't too much of an effort to create the virtual hormones. After all, you probably already have wired such a mechanism into your cyborg's body so that having an empty fuel cell will signal some pretty bad alerts, and that a full fuel cell gives good feelings. That sand in the gears hurts, and that when everything works perfectly smooth it's a great feeling. That when endangered, you can overclock your servos / gyros / artificial muscles to get out of the situation, but which wears out your parts very quickly when turned on 24/7.

Concerning the sexual hormones -- not quite sure about them. On the one hand, the urge to reproduce is hardwired so deeply into the human brain that it becomes a MUST to give your cyborgs a way of having sex (two or more entities meeting in emotionally very intimate settings that result in highly pleasurable actions that get rewarded by a slew of feel-good hormones and emotional bonding). Are there sexual hormones necessary for that? No idea. After all, cyborgs don't need the hormones necessary for keeping their primary and secondary gender characteristics, and they don't need the testosterone for muscle building. However, in some job areas they might want to have the testosterone's effect of increased aggression and dominant behavior. Or the estrogene for whatever wikipedia says it is good for in Cognition and Mental Health.


If you want a human uploaded into a cyborg, you will need to take all the hormones (their simulated effects) with you -- if you haven't already done that just to make sure the human keeps their body alive/maintained and the consciousness accepts it as an actual physical body.

  • $\begingroup$ I think you are misusing Ellipsis. $\endgroup$
    – JDługosz
    Oct 29, 2016 at 9:00

As a very simplistic answer. Wouldn't brains without hormones be computers. Or put another way. Are not all our emotions controlled by hormones. I look at hormones like a palette of paint with an infinite array of different feelings or colours. A cyborg without hormones would not have desire, hurt, pain, love, happiness or anger. Don't have a clue if this is correct or helps but it is an opinion.

  • $\begingroup$ Answers should be more than opinions. This isn't just a discussion site. $\endgroup$ Oct 29, 2016 at 6:38
  • $\begingroup$ Hi, tim, welcome to Worldbuilding. The point is not whether answers are right or wrong, it's whether you can make a good argument to justify them. Answers should include facts, reasons why something is so, and information to support what you're saying. WB isn't a discussion forum. It takes time to learn the ropes Answers need facts, information to support them, and reasons to justify your argument.. Take it one step at a time. You will have fun and your mind will be stretched too. $\endgroup$
    – a4android
    Oct 29, 2016 at 6:46

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