Schopenhauer is remarkable for his suspicion of romantic love as something maddening and dangerous. Over 30 years before Charles Darwin’s On The Origin of Species and centuries before neuroscience, he knew that what makes people fall in love is not their best interests, but the interest of biology.

What is now called the ‘reproductive imperative’ is what makes love a natural obsession, because finding The One, an ideal match, leads to the production of ideal result children.

Schopenhauer terms this simply as a masculine person will probably love a feminine, a short a taller, because it leads to the average happy medium. The best average for the next generation. “Balanced children”, who will, in turn, be more appealing to more potential mates when they grow up because their biological averageness has broader appeal; though Schopenhauer did not think through that far. The recurrence of love in media, song, and discussion is not surprising because, as he writes in The World as Will and Idea: “What is decided by it is nothing less than the composition of the next generation … the existence and special constitution of the human race in times to come”, which fits perfectly – yet preceded – knowledge of Darwinism, D.N.A and evolutionary psychology.

Remarkably, research like that collected in Dr Earl Nuaman’s aptly named Love at First Sight has shown love-at-first-sight is real for a surprisingly major few, more commonly in men; and that those relationships do last longer on average. (How much is the intersection of culture with biology or vice versa remains elusive.) How much of love is precdent is intersting. As Rochefoucauld says, “people would never fall in love if they hadn’t read about love in novels.”

Lasting affection is certainly real, not that it requires evidence – evidence helps too. Dr Helen Fisher et Al of Stony Brook University at New York, as explained in her fascinating Why We Love: The Nature and Chemistry of Romantic Love. Functional magnetic resonance imaging scans present an “in-love glow” in couples who stay together an average of 21 years–the same glow that appears in the first year of love appears years later when presented a picture of their beloved. Not to say that fMRI patterns aren’t complex, but it provides a more reliable picture than speculation.

And love really is blind: studies have shown that love by nature is a delusion about someone, a distortion of facts and objectivity. The language invoked in descriptions of the special someone are obviously non-factual to anyone else but all too real to the infatuated, “best person ever”, “prettiest person in the whole world”, exaggerative poems, songs, films, letters that are replayed time-again testify to the fact. Similar to the effect of optimist delusion, love delusion can be a good thing (certainly to anyone who has experienced it, the best thing), in making life meaningful–“it was meant to be”; and more practically in seeing past inevitable flaws.

Love is a tricky delusion, though, since for the vast majority we do not fall in love like this but fall in lust. Of now married couples in the U.S. 50% divorce, 10-15% separate without paper and 7% just endure–only the remainder are happy in love.

But the statistical majority of love delusion victims cannot be rationalised out of what could be an awful decision, because nature – what Schopenhauer calls the Will-to-Life, and scientists call the reproductive imperative – has a will stronger than human reason or rules of best interest.

Love is regularly not even treated as a decision or practice at all but a binary of passion or absence thanks to the cultural dominance of romanticism for the past 200 years, and the natural foibles of our neurobiology.

The physiology of lust-love means just touching someone a lot or having sex can lead to a fake love because the oxytocin, vasopressin, and dopamine secreted will feel the same regardless.  It’s not fake, it can feel wonderful and real, but it is not sustainable. This is why we often fall in love not with who makes sense, with who is ideal on paper, but as the effect of a stream of circumstance and chemical interaction (what is best for our genes). Regularly being in the same environment – not personality, or suitability – is the most major predictor.

Schopenhauer finds this tragic and miserable: “after orgasm the Devil’s laughter is heard”. Forces beyond the rational mind can take your life on a worse track because bodies implicitly want to make babies (especially in an age without reliable contraceptives, this makes more sense).

Current fashion romanticises such falling in lust as falling in love, but it will not last as long as it feels in thrall, or sit-coms and films depict: the lifelong romantic project is usually going half on paying, raising kids, and taking out binbags and arranging the dishwasher far more than it is earth-shattering sex or holidaying in Milan. It would be good to have those expectations when making a verbal, or marriage signed, contract to commit.

The biology of lust can make people committed or married with someone who they feel they love but do not truly like. (In fact, women on the pill are scent blind to compatible pheromones from men. Women on the pill are drawn to biologically similar men out of a care instinct, as the pill turns off the desire for diverse genes.)

Love, affection, friendship, desire, these all very different.

Long-term lust becomes short-term love, whereas friendship, sacrifice and lust become long-term love. While passion remains, with time it does become more compassionate love.

This is inevitable, or it will not last. The above mentioned statistics agree.

The advice from Schopenhauer and neuropsychology is indeed to take it slow, cautiously, if it at all. Schopenhauer may have died a virgin. Even unaffiliated monks and nuns can be happy – even happier than those that follow family making convention; and for the gifted few that is what Schopenhauer recommends. Not surprisingly he died alone, true to his words.

For those of us who seek love think about it before your body decides for you: consider how much you really get along, how you will spend your hours on earth together, if you live or will live in the same region, if friends would long-term fit and family get-along. And of course, how willing they will (really) be to take out binbags and rearrange the dishwasher.

Love being blind is not a good thing unless it lasts; circumstance and attitudes play a larger hand than we realise.

Consider that, long-term, arranged marriages and love marriages become less distinct. As Sheen Lyengar delineates in her book The Art of Choosing, ten-years-in arranged marriages rate happier than love marriages by more than 23 points. This doesn’t mean they genuinely are happier, but that self-report happiness is actually comparable.

Why? Because love stays when you can only improve; and you don’t expect fantasy but compromise right from the start till the end.