Sigmund Freud has always considered happiness as comprising of two main categories: absence of displeasure and the feeling of pleasure. Truly, these define happiness but asides these, can someone's happiness be maintained even in the presence of displeasure? This is why we'll be looking way beyond just happiness as some people know it. A friend of mine once told me that "joy" is a higher level of happiness, because it is not dependent on what is happening or not happening but it is borne out of the heart.
More often than not, happiness is related to what is happening. For example, if you are gifted with some money, you will tend to be happy but what happens when the money goes? Some people's happiness tend to be short-lived and not sustainable because it is not from within. Joy, on the other hand, is a choice you make without recourse to the prevailing situation.
Pleasure has been linked to happiness for so many years. Even the renowned psychologist Kringelbach acknowledges this. This is the reason hedonism (seeking of pleasure) has been linked to happiness. Even eudemonia has been linked to happiness but more often, this tends to exclude the fact that life, to some extent, is unpredictable. Now tell me, when things do not move as you have planned, what will be your state of mind?
It is not uncommon for people to seek for more happiness even in the midst of happiness but tend to be sad when their quest for more happiness becomes futile. This is why happiness, just like other human needs, are insatiable. Happiness leads to quest for more happiness but more often than not, it is only based on hedonism or pleasure-seeking. Some scientists have also argued that hedonic mechanisms are not just related to the psychology of happiness but may also stem from the human brain. Naturally, our brain is wired to respond in certain ways to certain situations. Like someone will feel happy when something good happens.
Now the question that always comes to mind is "can happiness be measured?" I mean, is there a standardized measurement of happiness? This is actually where some people surmise that happiness should not be regarded as a concept of science and people only feel happy because they have convinced themselves that they are happy. Now, this also draws back to the point I raised that happiness, more often than not, is linked to happenings (like pleasure, etc).
When you get to a point where pleasure is absence, then the choice lies within you to either allow the situation to define you or to move beyond it. This is why I mentioned "joy" earlier. A state of joy is achieved, first, from the heart, then from the optimism that even though things may not be in your favour at the moment but you believe that brighter days are coming. This kind of optimism will naturally release the required energy you need to keep trying.
You can also read this article on the psychology of happiness
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