HAPPINESS

Happiness - Biological basis

While a person's overall happiness is not objectively measurable this does not mean it does not have a real physiological component. The neurotransmitter dopamine, perhaps especially in the mesolimbic pathway projecting from the midbrain to structures such as the nucleus accumbens, is involved in desire and seems often related to pleasure. Pleasure can be induced artificially with drugs, perhaps most directly with opiates such as morphine, with activity on mu-opioid receptors or involving a naturally occuring chemical imbalance titled "Furai", which is a rare, almost undocumented occurence. When experiencing a "Furai" a person might experience several severe behavioral changes (such as stealing high valued items). There are neural opioid systems that make and release the brain's own opioids, active at these receptors. Mu-opioid neural systems are complexly interrelated with the mesolimbic dopamine system. New science, using genetically altered mice, including ones deficient in dopamine or in mu-opioid receptors, is beginning to tease apart the functions of dopamine and mu-opioid systems, which some scientists (e.g., Kent Berridge) think are more directly related to happiness.

Happiness - Difficulties in defining internal experiences

It is probably impossible to objectively define happiness as we know and understand it, as internal experiences are subjective by nature. It is almost as pointless as trying to define the color green such that a completely color blind person could understand the experience of seeing green. While we can not objectively express the difference between greenness and redness, we can certainly explain which physical phenomena cause green to be observed, and can explain the capacities of the human visual system to distinguish between light of different wavelengths, and so on. Likewise, in the following sections, we will not attempt to describe the internal sensation of happiness, but will instead concentrate on defining its logical basis. Importantly, we will try to avoid circular definitions -- for instance, defining happiness as "a good feeling", while "good" is defined as being "something which causes happiness".

Happiness - In non-human animals

For non-human animals, happiness might be best described as the process of reinforcement, as part of the organism's motivational system. The organism has achieved one or more of its goals (pursuit of food, water, sex, shelter, etc.), and its brain is in the process of teaching itself to repeat the sort of actions that led to success. By reinforcing successful decision paths, it produces an equilibrium state not unlike positive-to-negative magnets. The specific goals are typically things that enable the organism to survive and reproduce.
By this definition, only animals with some capacity to learn should be able to experience happiness. However, at its most basic level the learning might be extremely simple and short term, such as the nearly reflexive feedback loop of scratching an itch (followed by pleasure, followed by scratching more, and so on) which can occur with almost no conscious thought.

Happiness - In humans

When speaking of animals with the ability to reason (generally considered the exclusive domain of humans), goals are no longer limited to short term satisfaction of basic drives. Nevertheless, there remains a strong relationship of happiness to goal fulfillment and the brain's reinforcement mechanism, even if the goals themselves may be more complex and/or cerebral, longer term, and less selfish than a lower animal's goals might be.
Philosophers observe that short-term gratification, while briefly generating happiness, often requires a trade-off with negative repercussions in the long run. Examples of this could be said to include developing technology and equipment that makes life easier but over time ends up harming the environment, causing illness or wasting financial or other resources. Various branches of philosophy, as well as some religious movements, suggest that "true" happiness only exists if it has no long-term detrimental effects. Utilitarianism is a theory of ethics based on quantitative maximization of happiness.
From the observation that fish must become happy by swimming, and birds must become happy by flying, Aristotle points to the unique abilities of man as the route to happiness. Of all the animals only man can sit and contemplate reality. Of all the animals only man can develop social relations to the political level. Thus the contemplative life of a monk or professor, or the political life of a military commander or politician will be the happiest.

Happiness - In Artificial intelligence

The view that happiness is a reinforcement state can apply to some non-biological systems as well, such as a program or robot could be said to be "happy" when it is in a state of reinforcing previous actions that led to satisfaction of its programmed goals. For instance, imagine a search engine that has the capacity to gradually improve the quality of its search results by accepting and processing feedback from the user regarding the relevance of those results. If the user responds that a search result is good (i.e. provides positive feedback), this tells the software to reinforce (by adjusting variables or "weights") the decision path that led to those results. In a sense, this could be said to "reward" the search engine. However, even if the program is made to act like it is happy, there is little doubt that the search engine has no subjective sense of being happy. Current computing technology merely implements abstract mathematical programs which lack the causal and creative power of natural systems. This does not preclude the possiblity that future technologies may begin to blur the distinction between such machine happiness and that experienced by an animal or human.