A majority of people generally say they want a happy life. A majority of people also say they want to become parents at some point. The trouble is, according to nearly every study ever performed on the matter, becoming a parent reduces happiness and marital satisfaction. So why do people become parents? Sociologists call this the “parenthood paradox.”

The best answer so far comes from Roy Baumeister, a pioneering and prolific sociologist from Florida State University. His research suggests that people do not just pursue happiness. People have a separate instinct to pursue meaning – a sense of coherent life narrative that gives one a sense that they’ve significantly contributed to others’ experience. What’s more, people will tend to delay or defer happiness to make choices that bring meaning.

Now, thank God these two ideas are not mutually exclusive. As a matter of fact, they generally correlate. People who report having a meaningful life generally also report being happy, and vice versa. And certain characteristics, like stong social connections, positively influence both happiness and meaning. But it’s important to note that there are important differences between these two concepts, with starkly different implications, and it is absolutely possible have one without the other. Not infrequently, people live at the extremes: having a happy, shallow life (hedonism) or a miserable but self-satisfactorily meaningful one (martyrdom).

In a recently published article in the Journal of Positive Psychology, Baumeister reveals the results of a large survey that detail the important psychological distinctions between happiness and meaning.

Happiness has to do with how one is feeling at the present moment; that the positive sensations they’re experiencing outweigh the negative ones. Happiness is the natural state of having one’s needs met in the present moment, and of generally feeling good (this is called the “affect balance”). It is quantified in terms of present feeling and also life-satisfaction. Happiness can be boosted by the gratifying of needs: eating, drinking, shopping, compliments from others, etc. Happiness correlates with certain responses: finding one’s life to be relatively easy, reporting oneself as being healthy, feeling good often and being able to buy what one needs or wants. Happy people generally receive more from society, in terms of attention, positive energy, and resources, than they give back.

All of these responses were irrelevant to, or negatively correlated with, meaningfulness. Meaningfulness is a reflection of the symbolic, narrative self rather than the need-and-gratification self. It is culturally based rather than based in nature, and reflects one’s self-perceived value to the rest of the group. Meaningfulness correlates with devoting time to thinking about one’s past and future, percent of time spent with loved ones, tendency to help others in need, parenting, reporting higher stress levels, considering oneself to be anxious, wise and/or creative, and reporting that “arguing is something that reflects me.” These items reflect a sacrificing of the self; people with self-reported meaningful lives generally give more time, attention and resources to society than they get back.

We know why we seek happiness; it’s an evolutionary instinct to help us make sure our needs are met. It is unclear at this time why we seek meaning to our lives: it could be that meaningful pursuits lead to a higher-long-term form of happiness, or it could be that we are wired to pursue meaning for its own sake. Since humans are tribal animals, the search for meaning–which is to say communal value–is also probably evolutionary in nature.

Now that this dichotomy is illuminated, it seems almost painfully obvious. We’ve seen echoes of it throughout history. The two most famous philosophical schools of ancient times, the Stoics and the Epicureans, reflected this dichotomy in their teachings. Epicureans taught that the highest pursuit was the avoidance of pain, and that the best use of life with in the enjoyment of its simple gifts. Stoicism, by contrast, emphasized meaning at the complete sacrifice of happiness. It promoted the virtues of duty, brutal honesty, and self-sacrifice.

Ayn Ran’s “Objectivism” is an outdated philosophy based on rational self-interest.

The dichotomy also has economic and philosophical implications. Most of our economic models today are still based on the outdated supposition that people pursue their rational self-interest; that they are only really interested in satisfying their needs. Behavioral economics steps beyond this to say that our economic decision are not perfectly rational because of the way the brain takes logical shortcuts. But this idea steps us even further: that people are capable of making economic decisions against their own rational self-interest because they find it meaningful to do so. The notion of meaning makes obsolete all economic and philosophical theories built entirely upon the idea of rational self-interest.

The need for meaning may also come from a psychological first-need to impose structure and narrative on top of the chaos and entropy of life. I remember having a biblical conversation once with someone a lot more versed in it than I am. We were discussing the Old Testament book of Ecclesiastes. Ecclesiastes was probably written around the 3rd century BC (tradition holds that it was written by Solomon in his old age). It’s a poetic, nihilistic writing that details the author’s search for meaning through life. He accumulates wealth, friends, builds institutions, and does all a man can do to leave a legacy. He concludes at the end that “all is vanity,” and that given time all works of man are fundamentally impermanent. They will be eroded to nothing, like the empire of Ozymandias in the Shelley poem. The interesting thing about Ecclesiastes is its last two lines. They are controversial because they don’t fit with the rest of the writing, and scholars believe they might have been added later: “The conclusion, when all has been heard, is: fear God and keep His commandments, because this applies to every person. For God will bring every act to judgment, everything which is hidden, whether it is good or evil.” While most of the book implies that there is no order–“nothing new under the sun”–these lines imply rules, meaning and higher order.

My friend was explaining to me that scholars have gotten this controversy wrong: it’s not important whether those lines are part of the writing or added later; the important thing is that someone felt compelled to add them. Man cannot simply leave the thought at “all is vanity.” We are compelled to superimpose meaning. We all have to get out of bed the next day. We need to superimpose narrative and contribute something, even though, relative to time, we are dust.

So what do we add to the end of Ecclesiastes to get us out of bed and help us deal with a random and sometimes brutal universe? Little beliefs. Little meanings. Little rules for conducting life. Voltaire gave this to us with Candide. At the popular height of optimism mankind believed that it had the world figured out. There was a higher order, and everything happens for the best. Good, now we can put all these annoying questions to rest in the self-assured comfort of a universal order that will take care of us and give us the best possible outcome to our lives. What happens? Candide gets ripped away from his comfortable isolation and bounced around the cruel world of the Inquisition. He finds no satisfaction to his questions about good and evil (i.e. universal order). At the end, what does he decide? To become a farmer, and seek satisfaction in his garden. Those would be his last two lines of Ecclesiastes: “Forswear your vain searches and cultivate simply.” Not quite “Keep the Lord’s commandments,” but the exact same idea.

Fortunately for us, happiness and meaning are correlated. This means that the most ideal–the most fulfilling–application of life lies somewhere in the tension between meaning and happiness. Between what we want, and what society expects of us. It seems like such an obvious truth when one says it out loud, but somehow its helpful to understand that the dichotomy is psychologically real. It helps explain why we do what we do.