Are we poisoning the well?
“If you can’t understand why someone is doing something, look at the consequences of their actions, whatever they might be, and then infer the motivations from their consequences. For example, if someone is making everyone around them miserable and you’d like to know why their motive may simply be to make everyone around them miserable including themselves.”
― Jordan B. Peterson
The question of how two different people can face the same situation and come out with entirely different viewpoints has fascinated me for quite some time. One version of this is how we see the world. Do we see our life as a prison or a playground? Moreover, if so, what is our outlook? Will we try to make the best of it, or will we degrade to perpetuating our misery, while filling the lives of the people around us with that same pain? Are we generally optimistic, or pessimistic? How might we guide our lives to be lived more in one of these areas as opposed to another? To begin this discussion, we should understand something about what optimism and pessimism are and how they show up in the world.
“Optimism and pessimism - expecting a positive or negative future - are distinct modes of thinking that are best conceptualized, not rigidly and dichotomously but rather, as a continuum with many degrees of optimism and pessimism….An operational definition of optimism and pessimism is [the] anticipation of good or bad things to happen in the future, respectively...” 
How do we come to have expectations of a positive or negative future? It’s not as simple as we might want to imagine.
The Origins of a Negative Mindset
“Our survival and wellness require a balance between optimism and pessimism. Undue pessimism makes life miserable; however, excessive optimism can lead to dangerously risky behaviors.” 
We might be able to imagine from this quote that our ancestors who had a healthy dose of pessimism survived. Historically, if we were merely optimistic about finding our next source of food and did nothing about it, then it is likely we would perish. So we had to and still in many situations and places in the world have to have some aspect of pessimism in our minds to be able to survive. On the other hand, like with everything in life, the extremes are not a productive place to be.
Our outlook on the world has a tremendous impact on our mental state. We could say “This situation is different than what I think that I deserve; therefore, I’m pissed off.” Alternatively, we could say “This situation is different than what I think that I deserve; therefore, I’m actively working to make it better, or change it.” The first example is non-acceptance and the second is acceptance. There is a fine line between the two with the former being a seed for pessimism and the latter potential for optimism.
Let us not forget that if we drop a glass on the floor, it is indeed broken. No amount of positive thinking will magically rebuild such an object. The same can be said for being held captive in a concentration camp, or as a prisoner in general. There is no way for us to think ourselves out of that situation, acceptance and a realistic level of hope will keep us from perishing due to such horrors.
“A man who becomes conscious of the responsibility he bears toward a human being who affectionately waits for him, or to an unfinished work, will never be able to throw away his life. He knows the “why” for his existence, and will be able to bear almost any “how”.” 
However, on the other end of the spectrum, unrealistic optimism combined with a strong sense of hope is what fuels the fires of anger and rage.
“What lies behind rage very often is an unusual quality because we tend to think that very angry people are sort of dark and pessimistic characters. Absolutely not. Scratch the surface of any regularly angry person, and you will find a wild optimist. It is, in fact, hope that drives rage. Think of the person who screams every time they can’t fight their house keys or every time they get stuck in traffic. These unfortunate characters are evincing a curious but reckless faith in a world in which keys never go astray, the roads to mysteriously traffic-free. It is hope that is turbocharging their rage.” - Alain de Botton
If it is the case that extreme optimism can lead to anger, then does extreme pessimism lead to happiness? If we take a viewpoint of expecting nothing, then this leaves us no motivation to act. We only work when we think that our future will be in some way better than our present. Regarding taking action, there are some distinctly different ways that optimists and pessimists conduct themselves.
“Optimism is associated with taking an active approach for both maximizing one’s well-being and minimizing stressors. Pessimism, on the contrary, is associated with using mostly escape and avoidance strategies when dealing with distress, as well as with hesitations and a passive attitude when faced with an opportunity. Furthermore, having confidence about eventual success prompts the optimist to continue trying even when the going gets tough, while doubts about the future discourage the pessimist from persisting…” 
“Optimistic thoughts lead to active coping strategies, and the rewarding results weave a sense of self-efficacy and mastery over one’s environment (internal locus-of-control), which further reinforces the proactive attitude. In contrast, pessimism facilitates a passive attitude which hinders and minimizes positive feedback, thereby further exacerbating a ‘learned helplessness’ thinking pattern and depressed mood…” 
In other words, when we face a new environment through exploration we begin to learn not to fear it. If for some reason, when we are exploring this new domain (new space, person, experience, etc.) an unexpected situation arises and we flee, then this territory remains unexplored and filled with fear. If we do not muster the courage to go back and continue exploration, then fleeing and avoidance can become a coping mechanism. When this is reinforced, we tend to move about the world less and less. This idea can degrade to a person being so depressed that they cannot get out of bed in the morning.
To have the desire to act in the hope of changing means that we hold the belief of a better future than the present. To some, this could mean the pursuit of perfection. While this is not necessarily bad, it can be detrimental if treated improperly. If we try to jump to being flawless, then we will most likely bite off more than we can chew. In doing this, we learn that we will fail and will potentially either burn out or give up. It is critical to have a goal in mind and break it down into small - much smaller than we think that we need - bite-size chunks. It goes with the saying that even a journey of a thousand miles begins with a single step. If we continually try to jump to the end, we will continue to fail.
“Repeated failures reinforce one’s belief in his/her incompetence, personal inadequacy, and inferiority. This vicious cycle further exacerbates negative thinking patterns and may lead to a sense of hopelessness, self-blame and eventually depression. Indeed, studies showed that unhappiness, low self-esteem, pessimism, and depression are all linked to the chase after perfectness [...]. Accordingly, therapeutic methods for overcoming pessimism and unhappiness concentrate on setting realistically achievable goals for oneself, cultivating a non-judgmental attitude and practicing unconditional self-acceptance - applying compassion, generosity, and love to oneself [...].” 
Now that we have explored the makings of a pessimist let us explore some of the real-life detriments of such an attitude by looking at working in groups or teams.
Real life Example
To a degree, we as humans tend to become like those with whom we surround ourselves. Therefore, it is essential to be cognizant of the folks that we allow into our lives. We must be clear on what we are willing to tolerate. Are we okay with someone who continuously complains? In most cases, we would probably like to be around someone who sees the good in the world a majority of the time. There are always positive and negative things happening around us, and it is our choice on which to focus.
“Everything can be taken from a man but one thing: the last of the human freedoms—to choose one’s attitude in any given set of circumstances, to choose one’s own way.” 
In everyday life, if someone negative comes into our space, it is relatively easy for us to move away from or avoid them. Of course it never feels good to have to cut someone out of our lives, but in the end, it might be useful for them to realize what sort of energy they are perpetuating. This case is the ideal scenario; meeting a negative person in our personal lives and having the ability to cut them off. There are other cases when we are put on a team, perhaps at work where someone is bitter, cynical and angry.
When we work in a team, it is even more imperative that we are careful who is a part of that team. The ironic notion is that usually, the members of the team have little to no say regarding its composition. If we have a highly functional team and we place one bad apple in the bunch, we will significantly reduce the team’s overall performance. This concept is from where the title of the article derives. It only takes a single drop of poison to infect the entire well. This postulate is a note to anyone who is a leader of a team. We must be ruthless in protecting the overall mindset and morale of the groups that we lead.
At what Should we aim?
So then, for what should we aim? Should we be inherent optimists or pessimists? The literature shows that we should focus on being moderate optimists even if that means living with a bit more risk and in a slightly warped sense of reality.
“Nonetheless, the empirical literature suggests that, in regard to one’s general attitude, being in the middle of the optimism-pessimism continuum (i.e. practicing ‘realism’) is not necessarily the best. A moderate dose of optimism, although it distorts one’s perception of reality to some extent, can be advantageous. Studies that investigated the correlation between optimism and health suggest that optimists generally have better physical health [...], less cardiovascular diseases [...] and improved immunological functioning [...]. Furthermore, optimists and their romantic partners indicated greater satisfaction in their relationships [...].” 
What can we do?
Unfortunately, much of what drives a person to such negativity, anger, rage, bitterness, resentment, etc. are developed from the inside. However, there are several things that we can do to shift a negative/pessimistic mindset.
There is a correlation between what we do with our body, and how that impacts our mind. Exercise has been shown to improve mood for many reasons. How we carry our body also has an impact on our mindset (head up shoulders back bolsters confidence).
“Since the body-mind relationship is bi-directional - mental states affect body states and body states affect mental states…” 
Our outlook on the world also has a lot to do with how active certain areas of our brain are. When our left hemisphere has a higher level of action, we tend to be more optimistic. The converse is true when our right hemisphere is the dominant region.
“...a relaxed state...enables optimistic thoughts to thrive and flourish. In addition, the [left hemisphere] has a more active role in dealing with the environment. This fosters and encourages a proactive mindset of taking the initiative in dealing with life’s challenges - a basic component of optimism - and the rewarding results further reinforce an optimistic attitude. Furthermore, the [left hemisphere] receives, from the early formative years of infancy, a relatively more positive sensory-motor feedback, due to its dexterity and smoothness of actions, compared to the [right hemisphere]. This motor fluency breeds a sense of confidence and high self-esteem - a feeling that one has a fair degree of control in life and capability to overcome potential obstacles on the way. Accordingly, optimistic thinking patterns and positive experiences that reinforce them are primarily connected with, and integrated into, neural systems within the [left hemisphere].” 
As a part of positive reinforcement, again goal setting is paramount. When we set a goal, and we achieve it, the confidence in our ability to manipulate our surroundings is increased. This idea contributes to our sense of power which positively feeds back into our understanding of optimism. This is to say, we tried to do something, it went right and now, in the future, perhaps we can work something and yet again it will go as planned (it is likely the converse will happen a majority of the time - that’s why we must not cease in our effort to try).
“Indeed, studies show a positive correlation between the sense of power - i.e. being able to influence one’s environment and overcome its challenges - and optimism; people with a higher sense of power are more optimistic than those with a lower sense of power, presumably because power shifts one’s attentional focus from the potential pitfalls into the potential payoffs [...]. Similarly, confidence is robustly associated with hope, optimism, and resilience [...]. In addition, a sense of power increases active and approach behaviors, while it reduces inhibition and withdrawal tendencies...” 
While these are things that we might be able to do to create a shift within ourselves, how is it that we should deal with this in a team or group environment? There are several angles to take. The first would be to understand where that person’s shortcomings in thought are and try to provide some guidance on overcoming small issues as part of working toward a more critical overall goal. Ideally, we would be able to place something in front of that troubled person that they value and allow them to pursue it. We could also make an effort to relate to them that the only real choice that they have in life is how they let reality affect their attitude. Unfortunately, most people in this mindset have chosen to make themselves and everyone around them miserable. This point leaves us with a final possibility of cutting that person loose - which is an appropriate case for those who do not wish to change.
“The pessimist resembles a man who observes with fear and sadness that his wall calendar, from which he daily tears a sheet, grows thinner with each passing day. On the other hand, the person who attacks the problems of life actively is like a man who removes each successive leaf from his calendar and files it neatly and carefully away with its predecessors, after first having jotted down a few diary notes on the back. He can reflect with pride and joy on all the richness set down in these notes, on all the life he has already lived to the fullest.” 
 D. Hecht, “The neural basis of optimism and pessimism,” Exp. Neurobiol., vol. 22, no. 3, pp. 173–199, Sep. 2013.
 V. E. Frankl, Man’s Search For Meaning. Simon and Schuster, 1985.