what i call 'psychological interactors' are those that can happify people by satisfying their emotional, intellectual and/or spiritual needs. most common among such happifiers are the following:
1/ emotional interactors: love, respect, friendship, fellowship, etc;
2/ intellectual interactors: knowledge (information), etc;
3/ spiritual interactors: fame, power, faith/religion, music, artworks (like movies, paintings, literature, sculpture,and architecture), etc.
these happifiers may be human or non-human beings, tangible or intangible merchandise, social or non-social activities, but they have several important characteristics in common:
1/ every one of them is uniquely human-related or, in other words, has no value/significance to any other other kind of animal - 'power' might be the only exception, but it should be recognized as a physiological need or biological instinct rather than a psychological agent in the case of an animal;
2/ they are all capable of giving a human individual a sense of satisfaction or fulfilment;
3/ the extent to which they can happify people is usually determined by the way how the human individual and the psychological interactor interact or are related with each other.
to some people, certain psychological ineractors mentioned above may prove to be much more important than others. that is to say, not every human individual needs all the psychological interactors to attain happiness in living reality, although such full fulfilment is undoubtedly desirable. partly because they are psychological agents that can contribute most directly to one's state of mind, partly because they can offer most people a sense of satisfaction which is identical with the sense of happiness itself, these interactors are the most significant happifiers. to most people, true happiness can be gained and maintained only in relation to certain psychological interactors, or at the psychological level.
since happiness is by definition a desirable psychological condition, it can and should be obtained only through the agency of psychological interactors.
some people can be 'happy' even though they have few or minimum physiological stimuli, physical objects, and/or psychological interactors; however, their 'happiness' might be more innate or character-related than something obtained in living reality. if that is the case, this kind of happiness is meaningless to most people, although it deserves study.
if we need to understand happiness better, it is obviously not only helpful but simply necessary to pay special attention to what affects our sense of happiness.
the very process of reflecting upon the issue of happiness and articulating my thinkings about it is a happifying one to me - i am happy partly because i have my own definition of and findings about happiness itself.
for me, this process is a dynamic one, as it might be full of change.