There are many definitions of happiness. According to the dictionary, happiness is "a state of well-being and contentment" (Merriam-Webster, 2018). Words like joy, satisfaction, and laughter are often times used in relation to happiness. Sonja Lyubomirsky (2008), in her book “The How of Happiness”, states that happiness is “the experience of joy, contentment, or positive well-being, combined with a sense that one’s life is good, meaningful, and worthwhile” (p.32).
In philosophy, including Objectivism, "subjective" tends to be used in a significantly different sense, but one which arguably reduces to the above formulation with the addition of a fundamentally Kantian perspective on the nature of mind. The Glossary of Objectivist Definitions (by Ayn Rand, with additional entries by Leonard Peikoff and Harry Binswanger, edited by Allison Kunze and Jean Moroney) stated, subjective means the arbitrary, the irrational, the blindly emotional.
Philosophers debated the nature of happiness for thousands of years, but scientists have recently discovered that happiness means different things. There are three major types of happiness according to Diener (1984), are high life satisfaction, frequent positive feelings, and infrequent negative feelings. Scientists have labeled to the various forms of happiness taken together as Subjective well-being (SWB).
There are different causes of happiness following all the three elements of happiness, and that these causes are not identical for the various types of SWB, hence, there is no single key, no magic wand—high SWB is achieved by combining several different important elements (Diener & Biswas-Diener, 2008).
One researcher, for instance, has stated that students tend to tell him that you can't measure happiness. He expressed his concern in the article that as a researcher, he can't student something that can't be measured.
Logically speaking, on an intuitive level, we know that happiness can be and is often measured by the question we commonly ask "How are you?" or, more intimately, "How are you feeling?" That happiness can be measured through questions and that one can get a response that one can rely upon to understand a person’s happiness is backed by science (Frey & Luechinger, 2007; Pavot & Diener, 1993). Here, we're just using an effective measurement tool, no whether we can measure happiness. This means that is our question good enough? How about trying a different approach instead? If we are asking about an emotional, then instead of asking a question like "Are you feeling happy or sad, depressed, anxious, angry, etc?" Try, asking questions like "Are you feeling happy, or unhappy?" "Sad or not sad?" "Angry or not angry?" etc.
This is because we can have more than one feeling at a time instead conflicting everything out by throwing a bunch of questions at one time.
Diener et. al. (2009) developed an affect scale that includes 12 feelings: positive, negative, good, bad, pleasant, unpleasant, happy, sad, afraid, joyful, angry, and contented. With all that said, in the end, it's up to each person to define what happiness, sadness, joy, anger, anxiety, calm, etc, is to them. Each person has their own sense of being happy and different to others. Meik Wiking (“The Psychology”, 2018), CEO of the Danish Happiness Research Institute, states that happiness can have many different meanings among different people. Happiness is also a subjective experience and is often interchangeably referred to as subjective-well-being.
In addition to this, there are also external influences on people's happiness, the circumstances in which they live. People tend to compare living in poverty and wealth, and this can also triggers happiness. Is it possible for some to be happy when they live in a run down apartment with ill health, or with a child who has a serious disease?It may be difficult for some people to imagine. In contrast to this, it it easier to be happy if one has supportive family and friends, blessed with good health and is provided with their needs.
However, Galt's Speech differs the belief of happiness can be measured. His speech (pp. 130-216 in the Signet paperback edition of FNI) describes happiness as follows:
Happiness is that state of consciousness which proceeds from the achievement of one's values.... [FNI p. 137]
Happiness is not to be achieved at the command of emotional whims. Happiness is not the satisfaction of whatever irrational wishes you might blindly attempt to indulge. Happiness is a state of non-contradictory joy—a joy without penalty or guilt, a joy that does not clash with any of your values and does not work for your own destruction, not the joy of escaping from your mind, but of using your mind's fullest power, not the joy of faking reality, but of achieving values that are real, not the joy of a drunkard, but of a producer. Happiness is possible only to a rational man, the man who desires nothing but rational goals, seeks nothing but rational values and finds his joy in nothing but rational actions. [FNI pp. 147-148]
So, if happiness were subjective, it would mean that a person could be happy in any way he or she pleased - that there are no limit to a person's ability to become happy. Pe4rhaps granting that choosing to be happy isn't effective but just a pretend. There is also the case that presuming happiness is subjective, a person can become happy by choosing whatever he wishes to make him happy -- so, for instance, a thief chooses to steal, and he feels happy when he gets home with his new loot. Of course, though, beneath his superficial feeling of happiness, there's a fear that he will get caught.
The point here is, happiness depends on more than just the choices of the person who wants to be happy. Human's happiness has specific requirements -- requirements which must be learned if one is to become truly happy, and the way to become happy is by meeting those requirements.
To say that happiness is subjective is to claim that the requirements of happiness are purely a matter of personal choice. But in fact, they are not. You cannot choose to be really happy as a thief -- you can only pretend to be.
Many people spend a lot of time being unhappy. If happiness were subjective, this simply would not be the case. The reason people stay unhappy is that they fear correcting a mistake. It also because they grow used to the their unhappiness, thus, they become resigned.