# "Is Love a Mechanism of Evolution?" **URL:** \ **Category:** Great Debates\ **Created:** [September 19, 2003, 2:47pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603 "2003-09-19T14:47:19Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![LifeInHIM86](https://avatars.discourse-cdn.com/v4/letter/l/a4c791/32.png) [@LifeInHIM86](https://boards.straightdope.com/u/LifeInHIM86)\ **Post date:** [September 19, 2003, 2:47pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/1 "2003-09-19T14:47:19Z")
Hello all. I’m working on a paper for my gen psych class re: romantic love. Our beginning text is from[this book](http://www.dushkin.com/text-data/catalog/0072480645.mhtml?SECTION=TOC) but I don’t know of a full text available online. The “yes” side in this book is that love is a primarily biological sensation, designed to help us bear and raise children, and that we’ve evolved to serial monogamy. The “no” side says biology is a factor, but culture and individual will are more important, that serial monogamy is not based on biological activity, and love not just a vehicle for ensuring reproduction. I don’t think I’m explaining this so well, but maybe will post my paper when it’s done. Any thoughts on the matter? What is the nature/purpose/etc of love? ---
**Author:** ![Azael](https://avatars.discourse-cdn.com/v4/letter/a/a8b319/32.png) [@Azael](https://boards.straightdope.com/u/Azael)\ **Post date:** [September 19, 2003, 3:05pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/2 "2003-09-19T15:05:32Z")
I seriously doubt that we are supposed to be doing your homework. ---
**Author:** ![LifeInHIM86](https://avatars.discourse-cdn.com/v4/letter/l/a4c791/32.png) [@LifeInHIM86](https://boards.straightdope.com/u/LifeInHIM86)\ **Post date:** [September 19, 2003, 3:07pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/3 "2003-09-19T15:07:41Z")
heh - you’re definitely not doing my homework. It’s due in 20 minutes and I’m just working on my conclusion. I’m actually just really curious as to some other perspectives - at this University, it’s likely that most everyone will fall on one side, and I’m sure that’s not representative of the whole population. I’m just curious as to what others believe and why. ---
**Author:** ![TVAA](https://avatars.discourse-cdn.com/v4/letter/t/c57346/32.png) [@TVAA](https://boards.straightdope.com/u/TVAA)\ **Post date:** [September 19, 2003, 3:51pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/4 "2003-09-19T15:51:23Z")
What _isn’t_ a mechanism of evolution? ---
**Author:** ![toadspittle](https://avatars.discourse-cdn.com/v4/letter/t/c0e974/32.png) [@toadspittle](https://boards.straightdope.com/u/toadspittle)\ **Post date:** [September 19, 2003, 4:11pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/5 "2003-09-19T16:11:51Z")
> [@](#): > > The “no” side says biology is a factor, but culture and individual will are more important, **that serial monogamy is not based on biological activity,** and love not just a vehicle for ensuring reproduction. The serial monogamy bit is the weakest point of the nurture argument. It ascribes an extremely high value to the “culture” of non-human species, who follow various reproductive strategies. Is it Gbbon “culture” and “individual will” that causes them to adhere to monogamous relationships? Is it merely Walrus “culture” that has caused the species to form harems (with females significantly smaller in body mass than males)? It’s evolution. And, what the argument misses, is that, in cases where biology is not acting alone on human behavior, the “culture” we follow has certainly also been shaped by evolutionary forces. ---
**Author:** ![PoorYorick](https://avatars.discourse-cdn.com/v4/letter/p/ecccb3/32.png) [@PoorYorick](https://boards.straightdope.com/u/PoorYorick)\ **Post date:** [September 19, 2003, 4:18pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/6 "2003-09-19T16:18:17Z")
[Here’s your term paper, all ready to go.](http://www.jeassociates.com/eap/romance.html) 🙂 Actually, I’ve heard it argued that the concept of _romantic_ love was invented by the troubadours, which is where we get the “rules” that really don’t make a whole lot of sense once you think about them, such as, “You can only love one person at a time,” “If you quit loving someone, this means you never really loved them in the first place,” “True love lasts a lifetime,” and so on. Troubadours based the “grammar” of love based on what was going on with the ladies while the lords were crusading. Since the behavior of the nobility served as template for “correct” behavior, these rules they heard from the troubadours were taken to heart by the commoners. That’s the theory I heard, anyway. I’m not necessarily espousing it. ---
**Author:** ![Revtim](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/revtim/32/1042_2.png) [@Revtim](https://boards.straightdope.com/u/Revtim)\ **Post date:** [September 19, 2003, 4:18pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/7 "2003-09-19T16:18:24Z")
I’m with **TVAA** , I think _everything_ about a human being (or any other organism) is a result of evolution. ---
**Author:** ![erislover](https://avatars.discourse-cdn.com/v4/letter/e/71e660/32.png) [@erislover](https://boards.straightdope.com/u/erislover)\ **Post date:** [September 19, 2003, 4:35pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/8 "2003-09-19T16:35:08Z")
Biology, as far as anyone knows, is not the sole, or even most important, factor in how a person will behave. It cannot be, quite literally, because DNA cannot contain enough information to encode that much about a person. Cells do their own thing regulated by macro effects like the quantity or presence of certain chemicals, protiens, etc, around them. No cell “knows” whether it will be a brain cell, and no brain cell “knows” where it will connect to others. Evolution is too easy to interpret as all-powerful. If it were, it wouldn’t be a very useful scientific theory as it would fail to be sufficiently precise or selective itself. ---
**Author:** ![TVAA](https://avatars.discourse-cdn.com/v4/letter/t/c57346/32.png) [@TVAA](https://boards.straightdope.com/u/TVAA)\ **Post date:** [September 19, 2003, 4:42pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/9 "2003-09-19T16:42:24Z")
Quite correct. The most important determining factor is the sum of random of countless random molecular collisions. It’s an utterly useless determining factor, as it’s far beyond the capacity of even dreams of advanced nanotech to measure and predict usefully. ---
**Author:** ![Tigers2B1](https://avatars.discourse-cdn.com/v4/letter/t/9fc29f/32.png) [@Tigers2B1](https://boards.straightdope.com/u/Tigers2B1)\ **Post date:** [September 19, 2003, 5:00pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/10 "2003-09-19T17:00:14Z")
_erislover posted_ - > [@](#): > > Biology, as far as anyone knows, is not the sole, or even most important, factor in how a person will behave. **erislover** I’ve heard that conclusion expressed by some but I haven’t seen evidence from a study that supports that conclusion. On the contrary --I have seen studies – using ‘identical twin’ and using sibling – both raised together and apart — as well as studies using adoptees that suggest the opposite. I don’t think the ‘nature side’ is making the argument that genes direct the minutia of our thoughts and actions. I think the argument instead is that genes have a strong influence on our personalities, our general health – just as they seem to be recognized by almost all as affecting our physical appearance. ---
**Author:** ![Tigers2B1](https://avatars.discourse-cdn.com/v4/letter/t/9fc29f/32.png) [@Tigers2B1](https://boards.straightdope.com/u/Tigers2B1)\ **Post date:** [September 19, 2003, 5:04pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/11 "2003-09-19T17:04:32Z")
What we pay attention to in our worlds can be directed by our genetics without having to hardwire every thought and action. How we interpret what we pay attention to can be directed in the same fashion. I think that the argument that there is not enough DNA to direct all of these thoughts and actions isn’t necessary. ---
**Author:** ![erislover](https://avatars.discourse-cdn.com/v4/letter/e/71e660/32.png) [@erislover](https://boards.straightdope.com/u/erislover)\ **Post date:** [September 19, 2003, 6:10pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/12 "2003-09-19T18:10:51Z")
**Tigers2B1** , twin studies are useful in more than one way, though, because twins are likely to be exposed to very similar environments, too. They can reveal an association between certain sequences and certain behaviors, but this is never meant to be causal (a causal link is much more difficult to demonstrate without actually tampering with the genes). It is sort of like, most basketball players are tall people, so is there a basketball player gene? No, but height is part biology, and the game “basketball” has a preference there. Height isn’t all biology though, at least in a “predetermined” sense, since malnutrition can affect such growth. I’m not saying there isn’t a love gene or love sequence, because plausible arguments can be constructed that this relationship easily gives survival advantages. But I am saying that it is way too easy to appeal to evolution, and when it is done, it won’t carry the scientific weight that the theory proper actually has. In a more general sense, we can say that a creature’s biology sets the stage, but it is anyone’s guess whether “Hamlet” or “MacBeth” will be playing tonight, and even if there are selective pressures influencing the decision of which play will be on stage, we don’t get the luxury of automatically assuming it is because of the stage’s construction; ie, a person’s biology will set limits on what a person can do, but that is still quite wide, and just because a person does something doesn’t mean it has a biological source (in an evolutionary sense). ---
**Author:** ![erislover](https://avatars.discourse-cdn.com/v4/letter/e/71e660/32.png) [@erislover](https://boards.straightdope.com/u/erislover)\ **Post date:** [September 19, 2003, 6:17pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/13 "2003-09-19T18:17:45Z")
> [@](#): > > \*Originally posted by TVAA \* > It’s an utterly useless determining factor, as it’s far beyond the capacity of even dreams of advanced nanotech to measure and predict usefully. Hardly. Tell that to the ideal gas law. ---
**Author:** ![TVAA](https://avatars.discourse-cdn.com/v4/letter/t/c57346/32.png) [@TVAA](https://boards.straightdope.com/u/TVAA)\ **Post date:** [September 19, 2003, 6:27pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/14 "2003-09-19T18:27:43Z")
> [@](#): > > \*Originally posted by erislover \* > \*\*Hardly. Tell that to the ideal gas law. \*\* Try using the ideal gas law to predict the behavior of a single molecule. And when critical events depend on the behavior of that molecule… ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [September 19, 2003, 6:52pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/15 "2003-09-19T18:52:14Z")
Dangit, what TVAA and Rev said: culture and will are also part of evolution. Perhaps the question should be phrased as “are we biologically programmed to fall in love in a serial monogamous fashion, or is it more due to cultural influences and individual personality quirks?” ---
**Author:** ![erislover](https://avatars.discourse-cdn.com/v4/letter/e/71e660/32.png) [@erislover](https://boards.straightdope.com/u/erislover)\ **Post date:** [September 19, 2003, 6:53pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/16 "2003-09-19T18:53:00Z")
Yes, well, hardly the case in evolution or love, of course, unless you’re a maniacal determinist in which case love is the least of your worries. ---
**Author:** ![erislover](https://avatars.discourse-cdn.com/v4/letter/e/71e660/32.png) [@erislover](https://boards.straightdope.com/u/erislover)\ **Post date:** [September 19, 2003, 6:55pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/17 "2003-09-19T18:55:48Z")
Sorry, **Ludovic** slipped one in on me there. ---
**Author:** ![knock\_knock](https://avatars.discourse-cdn.com/v4/letter/k/22d042/32.png) [@knock\_knock](https://boards.straightdope.com/u/knock_knock)\ **Post date:** [September 19, 2003, 7:13pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/18 "2003-09-19T19:13:19Z")
The reason that people are able to fall in love is that we evolved that way because love promotes 1) procreation and 2) raising offspring so that they will be more likely to survive and procreate. Love, or something like it, may also promote cooperative survival. You could call these the purpose of love. There are innumerable details of how love is experienced and acted on, how loving relationships develop, and how concepts related “love” are thought of, that vary from culture to culture, and, to a lesser extent, from individual to individual. These are influenced to some extent by biology - perhaps they are best thought of as interactions of biology, culture, and an individual. You could call this the nature of love. ---
**Author:** ![Tigers2B1](https://avatars.discourse-cdn.com/v4/letter/t/9fc29f/32.png) [@Tigers2B1](https://boards.straightdope.com/u/Tigers2B1)\ **Post date:** [September 19, 2003, 7:34pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/19 "2003-09-19T19:34:56Z")
**erislover** – Well first let me present my disclaimer – I certainly don’t have the hands-on experience I’m certain some on this board do have in this area. With that – this is an area of interest with me and I do feel that I can add something to this conversation. > [@](#): > > twin studies are useful in more than one way, though, because twins are likely to be exposed to very similar environments, too. But I am talking about studies that were conducted using pairs of monozygotic twins -some raised together – and some raised apart. The results of a large number of these studies can be found using Google and only looking at .edu sources. – Note that I am taking exception with your original statement that - “Biology, as far as anyone knows, is not the sole, or even most important, factor in how a person will behave.” That sounds too much like a statement that has support – which I don’t think it does. The evidence seems to suggest the opposite as I stated earlier. Of course – I am very open to being wrong here. If you like I’m certain I can provide links to .edu sources which support what I’m reporting here. You’ll notice that the similarities / the correlations between the paired groups goes down in rough proportion to the amount of genes shared (100% in monozygotic twins; 50% in siblings; 0% in unrelated raised together) > [@](#): > > They can reveal an association between certain sequences and certain behaviors, but this is never meant to be causal (a causal link is much more difficult to demonstrate without actually tampering with the genes). I don’t think that the argument on the ‘nature’ side is that genes directly “cause” behavior – in the sense that there is a 1 to 1 correlation. There is strong evidence out there however that genes have a significant influence on personality. By “significant” I mean the correlation is greater than +.50. I do not think that you will be able to find .edu studies that significantly differ with these results. > [@](#): > > It is sort of like, most basketball players are tall people, so is there a basketball player gene? No, but height is part biology, and the game “basketball” has a preference there. Height isn’t all biology though, at least in a “predetermined” sense, since malnutrition can affect such growth. Sure – but that’s not the ‘nature’ (in the nature verse nurture debate) argument. As stated above – it’s not a black and white debate — and I think you agree with that. I’m certainly not making the argument that chronic alcoholism will not affect your physical appearance –---- it might even change your hair color from red to gray. There is no argument here that the more extreme the environment the more likely it will have a greater influence than suggested by studies using those who have not been exposed to extreme environments. But that, as I understand the OP, is not what we are talking about here. > [@](#): > > I’m not saying there isn’t a love gene or love sequence, because plausible arguments can be constructed that this relationship easily gives survival advantages. But I am saying that it is way too easy to appeal to evolution, and when it is done, it won’t carry the scientific weight that the theory proper actually has. Arguments appealing to the weight that people give to the word “evolution” don’t have to be used — as stated, there are studies, independent of any idea of evolution, that suggest that personality is significantly heritable. > [@](#): > > In a more general sense, we can say that a creature’s biology sets the stage, but it is anyone’s guess whether “Hamlet” or “MacBeth” will be playing tonight Well I don’t agree. If you have one side of a pair of identical twins – a person with training could make very good “guesses” about the twin he or she has never met. These “guesses” would be based solely on the results from the known twin. These assumptions would be less and less valid as the distance of genetic relationship goes down. > [@](#): > > …and even if there are selective pressures influencing the decision of which play will be on stage, we don’t get the luxury of automatically assuming it is because of the stage’s construction; ie, a person’s biology will set limits on what a person can do, but that is still quite wide, and just because a person does something doesn’t mean it has a biological source (in an evolutionary sense). Sure – until we actually witness a gene or a set of genes produce a behavior in human as we have in something like fruit flies (where I understand they have actually isolated behavior producing genes) than we can’t just assume either is the case. But yet again - that’s not the point. The issue - as I see it - is whether there is _evidence_ for a significant genetic influence. My first response was to your implication that there is evidence out there that genetics influences are not the “…most important, factor in how a person will behave.” I suggest that is not the case and in fact the evidence suggests otherwise. ---
**Author:** ![erislover](https://avatars.discourse-cdn.com/v4/letter/e/71e660/32.png) [@erislover](https://boards.straightdope.com/u/erislover)\ **Post date:** [September 19, 2003, 7:56pm UTC](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603/20 "2003-09-19T19:56:52Z")
Lest we all start donning dew rags and colored glasses, love also makes a ripe bed for animosity, jealousy, anger, violence, murder, and so on. It is not the be all end all in the wide world of procreation. **Lamia** made some very good comments about the history of relationships for the purpose of childbearing in a thread focusing on homosexuality, but her point was more general. [Here.](http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=211274&pagenumber=2) > [@](#): > > **knock knock** _said_ > These are influenced to some extent by biology Yes, well, everything we do is influence “to some extent” by biology. **Tiger** > [@](#): > > Note that I am taking exception with your original statement that - “Biology, as far as anyone knows, is not the sole, or even most important, factor in how a person will behave.” That sounds too much like a statement that has support – which I don’t think it does. The evidence seems to suggest the opposite as I stated earlier. “Biology is the or one of the most important factors in behavior” is itself the positive claim; I’m trying to be in the position of the null hypothesis: it is the claim to be rejected, and that is what this thread is here for, to reject that claim and make the case. I am not trying to assert a positive position. > [@](#): > > I don’t think that the argument on the ‘nature’ side is that genes directly “cause” behavior – in the sense that there is a 1 to 1 correlation. There is strong evidence out there however that genes have a significant influence on personality. By “significant” I mean the correlation is greater than +.50. I do not think that you will be able to find .edu studies that significantly differ with these results. Neither do I. But work with my play analogy. There might be a great correlation between curtain height and the types of plays that are done (say, romantic operas, or three act dramatic plays, etc). What is the relationship here? A correlation can point to accident (ie coincidence), hidden variables (something that is common to both and affects both), or causation. This is a very large set of hypothesis to work on, and to say something like “The ‘yes’ side… is that love is a primarily biological sensation, designed to help us bear and raise children, and that we’ve evolved to serial monogamy.” This is a very strong claim, and unless we are careful in how we use a term like “evolves” we can be led to make statements that are more than unwarranted. Like: > [@](#): > > as stated, there are studies, independent of any idea of evolution, that suggest that personality is significantly heritable. I simply find this claim stronger than any of the studies I’ve read. [Next page](https://boards.straightdope.com/t/is-love-a-mechanism-of-evolution/202603.md?page=2)