For example say I'm pessimistic person should I pretend to be positive since it makes a better work environment even though I'm not expressing my true opinion? Or that I don't enjoy talking story with coworkers should I force myself to do it more just to be social? Is there a part of work that fakeness is mandatory and when it's not.
What you are calling "fakeness" is just manners and impulse control that's required to work with people.
Work interactions are not simple social interactions, as the consequences are different. You won't see this in any contract, but getting along with people and fitting into the work culture is part of the job.
If it's an upbeat environment, being a pessimist, or at least vocalizing it, isn't going to get you that far. The inverse also applies. Being bubbly and light will grate on people if it's a more serious environment.
So, you have three choices:
- Sublimate your behavior/attitudes, which yes, is a bit fake
- Modulate your behavior/attitudes. In other words, stay real, but tone it down, hold your tongue, and try to frame interactions within the culture
- Find an environment which would be a better fit to your personality.
So, no, being "fake" isn't a requirement, but you have to make a decision as to how much effort you want to expend to fit into the culture, then act accordingly.
A few years ago I read a comment:
Those that make a career in corporate settings tend to share common characteristics: they have this friendly, non-threatening way of being. They avoid taking a stance on divisive topics. Making a career requires avoidance skills more than anything else.
Now, several years wiser, I agree with that. At least that's what I observed at large international corporations.
People who are successful in such settings avoid making enemies - even though making enemies is sometimes a consequence of e.g. pointing out a mistake that could cost company millions. There are a lot of articles about e.g. how people who signal problems/ whistleblowers are treated (spoiler: not very well). Generally, if you work a lot and change a lot you will have enemies. So these people normally aren't most effective.
Also, there is a lot of research that shows a very high percentage of people with psychopathic characteristics working on higher management levels. And psychopathic tendencies mean: The people are super friendly and charming at the first sight. They have to be - if they weren't, they wouldn't be able to manipulate others. Of course, they aren't always charming and friendly, but that's not visible to most people.
Of course, this does depend on the company culture, but that's the general rule, especially in higher positions.
I think the specific examples you mention are not necessarily bad traits at the workplace. Someone pointing out the potential pitfalls of a project can be very useful when everybody else is in the everything-is-awesome-mode. Also a colleague who isn't talking all the time can often/sometimes be quite welcome.
However regarding your question in the title, I think it's a bit of an open door but I will answer it anyway. Yes some form of "fakeness" is absolutely required at work. Among other things.
- If you think some customers/clients are ignorant or downright stupid, don't ever show this to them.
- If you have some very non-mainstream opinions about political/societal issues it's better not to vent them at work.
- Even if you can dress casually at work, it's better to wear clothes which are reasonable clean and not worn out.
- If you feel like crying because you made a huge mistake or received some fierce criticism, it is often better not to.
- If you have a very sexy/good-looking colleague, admire/oggle him/her/they1 in such a way that nobody notices.
It depends a lot on what you mean by "fakeness". You need, as in all social situations, to treat people with respect and professionalism, although even what that means depends on the company; if you came into my company (the one I work at, I'm not a CEO) and started calling everyone "Mr." this and "Ms." that, people probably wouldn't like it; however, if you started on a first name basis with clients at a bank, you'd probably have the opposite response. So even that base level depends on the company.
To discuss your precise examples:
Nobody likes a pessimist. If your response to every problem is "this will never work, we're fucked, the sky is falling get out now", nobody will like you, because you're just being difficult, you're not providing any value. The correct way to act is, if you see a problem, you should point it out, in a specific and actionable way. There's a big difference between "this application will explode and our clients will hate us" and "we haven't properly considered the traffic load to our database and maybe we should allocate additional replicas". Both could be considered "pessimistic", but the former is not helpful, while the latter is very helpful. Conversely, the guy who rubber-stamps everything and nods and says "ok" to everything is also not helpful, for mostly the same reason: you're not actually providing any value. So, to sum it up, rather than saying "everything is great" or "everything is awful", you should raise specific, actionable problems where you see them to help your team produce a better product.
Regarding being social, everyone has their own barriers on this and every company is different. The main thing is that everything in life is networking; it's not "what you know", it's "who you know". If you are a more social person, then when budget cuts come around and your manager has to decide between two people who perform equally as to who to fire, he'll choose the person who gels better with the team. People who like you will subconsciously give you better performance reviews, even if you aren't deserving of them, meaning you'll climb the compensation ladder faster. If you are job-hunting in the future and need to find something, having connections to help you search or provide references will be more helpful than not having those connections, and you can certainly make those connections through previous jobs. In short, having friends is better than not having friends. Do you have to do this? No, but your situation will be better if you do.
"Fakeness" isn't always required, it depends on your job. If you speak to clients/customers, then faking positivity is kind of mandatory.
Working with colleagues, you don't have too, but doing so has major advantages.
I'm pessimistic person should I pretend to be positive since it makes a better work environment even though I'm not expressing my true opinion?
Being a pessimist in general isn't good. It will turn people against you. No one wants to hear your negative thoughts, and people will tune you out, so they're less likely to listen to any opinions/ideas that you have.
The best thing to do is find a balance between being an Optimist and a Realist. Try and focus on the positives. It is possible to change the way you think.
Instead of voicing negative opinions, assume there is some value in whatever it is. Then instead of pointing out the negatives, ask questions. This raises the negative points for discussion without you being seen as negative.
You should also ask yourself if your onion matters. Sometimes people are looking for support and don't want your help or opinion.
I don't enjoy talking story with co-workers should I force myself to do it more just to be social?
Me neither however, doing so has resulted in promotion. If you make friends with your co-workers they will say good things about you, and this will likely filter up to your manager and bosses.
If you don't make friends or play the office politics, you stay bottom of the barrel.
even though I'm not expressing my true opinion?
Making employees express their true opinions is sometimes what the companies are striving for. See if it's encouraged in your company.
(I'm assuming technical opinions affecting the company's business, not any other kind of opinion here.)
For example say I'm pessimistic person [...]
That's okay as long as that doesn't demotivate yourself nor your colleagues. Just follow the generic advice of presenting your concerns in non-offending ways. E.g. if you're pessimistic about certain feature, don't just say "it won't work", but ask "would the client be able to do X if Y?" If that's a valid concern -- that question would hopefully raise a discussion and make a difference.
(Be careful not to overdo it. Questioning every decision is as destructive as not voicing a concern that others have missed.)