A rewarding, well-lived life is not necessarily a happy one because happiness and a meaningful life are often incompatible.
As the Nobel prize-winning psychologist and behavioural economist Daniel Kahneman has said: ''People often make choices that bear a mixed relationship to their own happiness.''
The parenting paradox is a prime example. ''Most people assume that having children will make them happier. Yet a wide variety of academic research shows that parents are not happier than their childless peers, and in many cases are less so,'' wrote Jennifer Senior in New York magazine recently, in an article titled: ''All joy and no fun: why parents hate parenting.''
And yet, as social psychologist Roy Baumeister proposed in Meanings of Life, the paradox can be resolved because people seek not just happiness, but also meaning, ''and so they become parents because the gains in meaningfulness offset any losses in happiness''.
This tug-o-war is something many people, not just parents, struggle to resolve. New research from Stanford and Florida State universities, led by Baumeister, has attempted to differentiate between happiness and meaning. ''Although happiness and meaning are important features of a desirable life and indeed are interrelated, they have different roots and implications,'' the researchers said.
They define happiness as a sense of subjective wellbeing, while meaning is a cognitive and emotional sense of purpose and value. Happiness, they say, is rooted in our animal nature.
''Among creatures with brains and central nervous systems … basic motivations [to survive and reproduce] impel them to pursue and enjoy those needed things, and the satisfaction of those needs generally produces positive-feeling states. Conversely, negative feelings arise when those needs are thwarted.''
Meaningfulness, on the other hand, is related to more sophisticated human attributes.
''Culturally transmitted symbols, via language, [are used] to evaluate one's life in relation to purposes, values, and other meanings that also are mostly learnt from the culture.''
The results of the study, soon to be published in the Journal of Positive Psychology, are as remarkable as they are revealing.
For instance, the authors found that ''doing things that express and reflect the self are important for making life meaningful, but they are mostly irrelevant and occasionally even detrimental to happiness''.
These expressions of self can range from reading to socialising to working to take care of the kids.
Similarly, helping others has a positive impact on our sense of a meaningful existence, but somewhat surprisingly, it has a negative impact on happiness. ''Happiness seems intertwined with the benefits one receives from others. Meaningfulness is instead associated with the benefits that others receive from the self,'' the authors said.
While happiness may involve taking and meaning may involve giving, the authors are at pains to point out that they are both worthy pursuits and the intricate ties that bind the two are not cut and dry.
''If anything, happiness is linked to not helping others in need. But, in everyday life, helping others makes the helper's life meaningful and thereby increases happiness.''
While happiness and a sense of meaning benefit from a strong social network and both suffer when a person feels isolated or lonely, time spent with loved ones was found to be important for meaning, but not necessarily for happiness.
''Possibly because loved ones can be difficult at times,'' the authors hypothesised.
Worry and devoting time to thinking about the past and future were also aligned with how meaningful participants found their lives - and how unhappy they were. Thinking deeply, on the other hand, had no correlation to happiness or meaning. ''Whereas happiness was focused on feeling good in the present, meaningfulness integrated past, present, and future, and it sometimes meant feeling bad,'' the authors said. ''Past misfortunes reduce present happiness, but they are linked to higher meaningfulness - perhaps because people cope with them by finding meaning.''
The authors hope that insights such as these will encourage a greater emphasis on our search for meaning. Positive psychology grew to counteract the field of psychology's emphasis on pain and suffering. The authors hope to bring the balance back, illuminating the fact that happiness alone does not make the good life.
Cultivating and encouraging the pursuit of meaning in the face of unhappiness may be a worthy goal for positive psychologists, they said.
''Clearly happiness is not all that people seek, and indeed the meaningful but unhappy life is in some ways more admirable than the happy but meaningless one,'' the authors conclude.
''The happy person thus resembles an animal with perhaps some added complexity. In contrast, meaningfulness pointed to more distinctively human activities, such as expressing oneself and thinking integratively about past and future. Put another way, humans may resemble many other creatures in their striving for happiness, but the quest for meaning is a key part of what makes us human, and uniquely so.''