What would motivate photosynthetic human beings to work on menial jobs like cleaning , dish washing etc. - jobs where earning for food is main motive?

For such creatures, food could be prepared from the Sun. Then why would people work on small-paying jobs? What would motivate them to do so?

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    $\begingroup$ Humans do not have the surface area to enable photosynthesis to produce significant amounts of energy. That is, enabling photosynthesis in a human shaped animal won't produce more than a fraction of one percent of that animal's energy needs. Look at a tree, and see how many leaves it has, and how large is total surface area of those leaves. $\endgroup$
    – AlexP
    Feb 20, 2020 at 10:44
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    $\begingroup$ You know, food is only a small part of the motivation I have to work. For many people around the world it's no motivation at all if they have their own subsistence farms. Take a look at your own paycheck and what you buy with it; take away the food bills, and the rest is your motivation. $\endgroup$
    – Tim B II
    Feb 20, 2020 at 10:45
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    $\begingroup$ @TimBII I suggest expanding this into an Answer, it certainly satisfies me! $\endgroup$
    – Ruadhan
    Feb 20, 2020 at 12:30
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    $\begingroup$ Water could also be a motivation. Photosynthetic people living in dry areas would have to work for water. $\endgroup$
    – Greenie E.
    Feb 20, 2020 at 15:27
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    $\begingroup$ Most folks in the USA spend more on housing than on food. Including subsidy, most spend more on health care than food. Many spend more on entertainment than food. $\endgroup$
    – user535733
    Feb 20, 2020 at 15:34

3 Answers 3


The world would remain (mostly) unchanged thanks to Maslow's Hierarchy of Needs.

People who could photosynthesise (and therefore not require food would have a dramatic impact on the global industry to be sure, but the one thing that would NOT happen is that people stop working. Many industries, like farming, would not exist but people would find other things to do, just the same as in Star Trek (a model for a post-scarcity society) people still continue to work, do jobs and sometimes deal with bosses they don't particularly like. Why? Because food (like shelter, oxygen, water, etc.) is only important to people when they don't have any. When they do, they move on from that onto other things that concern them.

This is true even today; as an experiment, check your monthly bank statement. Read off what you made for the month, and what you spent. Take away the food bills. There is still money you've spent of your paycheck. What was it on? That is the answer to why people would work. Whatever that difference is, that is why you work - to get more of that.

This is where Maslow comes into play. The truth is that the pyramid in the link is foundational in nature; that is to say, if the bottom bit is completely covered, you focus on the next tier up. If that is covered, you focus on the next, and so on. Your focus remains on the lowest tier which is not completely covered by your situation.

So, let's say that we don't photsynthesise, but that food, shelter, clean air and water, etc. is so abundant that you have access to all you want or need of any of it. Let's say that this abundance makes you feel completely safe and you have the love and respect of your family and community. All that makes you feel good about who you are and what you do in your life; what is left? Why work after that?

Because you will want to extend yourself; that's why. You'll want to learn new things, be good at something you really care about, make the world a better place, extend yourself so you can feel enriched by the process of becoming better than you are.

Ultimately, food is such a small component of what drives me personally to work that it's not funny. I work to make the world a better place, but then I'm one of the lucky ones who can say that I'm that far up the hierarchy. But, if you take food out of the equation, Maslow provides a handy reference of all the other things people will worry about and work at jobs to provide for in their life, all the way up to making themselves the best version of themselves they can possibly be.


Your assumption that sunlight alone is sufficient for survival is incorrect. It creates energy similar to the human digestive system, but does not create nutrients. The materials a plant or tree needs to grow and build additional branches or leaves can't simply be created from just sunlight. To actually grow, a plant or tree absorbs water and nutrients from the ground. If you want your humans to reproduce at all, and grow any size larger than a baby's, you will need more nutrients. You might need to eat less, but food is still necessary. Especially with the inefficient distribution of necessary nutrients in our food.

Other difficulties have already been pointed out by the comments, so I won't repeat them here.


While I totally agree, that humans are not capable of photosynthesis in any way possible, but this is not a science-based question, so let's handwave it.

Firstly, famine is only one of four. There are many other deadly dangers and demands connected to them:

  • Temperature - people need homes and clothes
  • Dangerous animals - homes, fences, guards, doctors
  • Diseases - hygiene (cleaners), doctors, hospitals
  • Aggressive people - fences (castles), homes, warriors, guards, doctors
  • etc.

All this demands create "second order demands" - education, crafts, logistics and many, many others. Satisfaction of all these demands requires "small paying jobs" like cleaners, loaders and etc. These may not be full-time jobs, and in some utopia citizens have to "serve to society" one day in month (or week) - this would more than fulfil all the demands for such jobs. Or they may be "youth jobs". This way or another, society would find a way to force people to do it, or this society would just fall.

Secondly, the Sun does not shine brightly anytime everywhere. "Sunny day" would become a value of it's own. Rich and powerful people would live in the tropics and the British Isles would become a ghetto. And if you want to see the Sun more often you would need to proof you usefulness for society, by doing this or that job (or by fighting at war for "good regions"). Or slowly die to constant malnutrition, like poor people in some regions of Africa IRL.

  • $\begingroup$ People in Scandinavia hardest hit... $\endgroup$
    – Thucydides
    Feb 20, 2020 at 19:49

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