Editor’s Note: With Valentine’s Day now upon us, what better time than now to talk to Dan Ariely? The professor of behavioral economics and psychology at Duke University gave a Google Talk on relationships and dating back in October. I surveyed the newsroom and a few friends for questions the married, the engaged and the single wanted answers to.

Below, Dan Ariely explains how not to fill out your online dating profile, how to make your friend less picky in who she dates, what questions to ask on a first date and why there is a correlation between moving to a nice school district and divorce. Still want to learn more about the best gift to give your significant other? Read my conversation with Ariely here, and check out economics correspondent Paul Solman’s report on the dating market.

— Kristen Doerer, Making Sen$e Editor

The following text has been edited and condensed for clarity and length.

What not to put on your online dating profile

Kristen Doerer: Alright, so our first question is: What is the best strategy for filing out an online dating profile if you’re looking for true love? What should you put in, what should you leave out?

Dan Ariely: So I think the question is: What function is the online dating profile going to fulfill in this search?

So we know a couple things. We know that when people read vague descriptions, they fill the missing parts in over-optimistic ways. So if you tell me you like music, I say, “Oh my goodness, you like music? I like music too!” And I assume it’s the same music. You say you have a good sense of humor, I say, “Oh my goodness, I have a sense of humor too, we’re probably going to be a great fit!” But what you mean by sense of humor might be very different than I mean.

This vagueness creates the opportunity for people to get disappointed. When we finally have coffee with somebody, we get crushed. And by the way, women tend to do this more than men, and people don’t tend to learn over time. This disappointment is a real killer, so you don’t want to exaggerate in your online dating profile.

And so, for example, we know that women love tall men. Do you know about this research on height called labor analysis?

Kristen Doerer: Tell me more.

Dan Ariely: So labor analysis is when I take all your characteristics, how old you are, your hair color, where you went to school and all your attributes, and I put them in a regression equation with your salary. I do the same for a lot of other people. So what predicts your salary? To what extent is education helping your salary, to what extent is height helping your salary and so on?

This is the kind of analysis that you do to show that women make less than men for the same job. So we did the same analysis for online dating. We took all the characteristics of people in an online dating profile, and we asked, “What explains these people’s success?” How much of it is explained by their height, their eye color, their hair, their education and so on? You can ask the question, for example, if I, Dan at 5’9”, wanted to be as successful as a man who is just like me, but 5’10”, how much more would I have to make a year to make up for this one inch? So what do you think is the number?

Kristen Doerer: I’m just going to throw out $5,000.

Dan Ariely: It’s about 40. Thousand. Yes, $40,000. Now, you can ask the question: Are women really that superficial? Right? It’s a lot of money. So part of the answer is yes, but don’t forget that with an online dating site, you can search by height. So if you say, I don’t want to see anybody below 5’10”, there might be a really wonderful, sweet guy at 5’9”, but you’ll never see him, because you said you wanted 5’10”. So yes, women love tall men to a crazy amount in my mind, but the way that the search engine works exaggerates this bias.

Men, on the other hand, don’t care so much about women’s height, men care a lot about BMI, body mass index. And websites don’t give you BMI, but they give you height and weight and you can calculate BMI. So men like a BMI that is kind of slightly anorexic. Around 19 is the most desirable one. But let’s say a woman who has a BMI of 20 wants to be as successful as a woman whose BMI is 19. How much more do you think she would have to make in order to compensate for this one BMI?

Kristen Doerer: Based on what you told me last time, I’m going to guess $20,000.

Dan Ariely: Actually men don’t care about how much women make. So it doesn’t matter. I’m sure at some level they care, but we couldn’t estimate it from the data. So the variable of how much women make doesn’t seem to come into play much in the equation of how many men approach women or how many write her a message or respond to her message and so on.

So if you think about this, you could say, let’s lie on the attributes that the other gender cares about. Women can lie about the weight, and men can lie about the height. But what happens is that this is really the key to disappointment. People don’t think two steps ahead; they just think one step ahead.

Kristen Doerer: Ok, so don’t lie.

Dan Ariely: It’s not just don’t lie, but also if you’re vague and you understand that people fill out the information in overoptimistic ways, even without lying, you will create disappointment. You want to eliminate ambiguity. People hope that you’ll talk to somebody online, they’ll fall in love with you, and when they meet you, they won’t care. It’s just not true.

What effect does one’s salary have on a relationship?

Kristen Doerer: You mentioned pay earlier. I’m curious what effect income and wealth have on a relationship or on a budding relationship.

Dan Ariely: In terms of relationships, we’re just starting to look at this, but here are my thoughts so far. Relationships are complex and multidimensional: there is how much you care for the other person, how much they care for you, who takes care of their kids, who takes care of the house, all kinds of things. And one of them is salary. But from all of those dimensions, which is the easiest one to measure? It’s salary.

So you could be in a relationship, and let’s just say for simplicity there are 10 dimensions of the relationship. Let’s say one person makes more money, and the other person is better on all other nine attributes. The money is going to be salient and precise, it has decimals. We know that in general, every time a dimension has decimals and precision, it’s given too much weight. So I think salary has a non-ideal weight in the relationship. And when there’s a salary imbalance in either direction, I think it creates tremendous unhappiness.

Actually, I have a friend who makes substantially more than her husband, and she told me that for years she was pissed off with it. So much so, she was thinking about ending the relationship. It just seemed terrible for her. By the way, it probably seemed terrible to him as well, but I didn’t talk to him about it. At some point, she was thinking about all the other things he was doing in the relationship, and she tried to quantify it. All of a sudden, she realized she’s actually the smaller contributor in the relationship. It wasn’t as clear, because money was so clear, so salient and so measurable.

How to be a meddling friend

Kristen Doerer: One of the people here asked, “How can meddling friends use behavioral economics to help their picky friends who don’t seem to like anyone they date?” So how can you help a friend who just seems to be too picky?

Dan Ariely: One way, of course, is social proof — the idea that you do what other people are doing. So let’s say you have a female friend who you want to make less picky and you see this guy. You could tell her how amazing you find him and that you are thinking, “If only I wasn’t married. I’m really interested.” You can show her that lots of other women, who are like her, are interested in him. That is social proof.

Another approach is what is called the “foot in the door.” The foot in the door is when you do something small, and afterwards, you ask yourself why you did this thing. You tell yourself, “Oh, I must be the kind of person who does X, Y or Z.” So how do you get your friend to make one step toward that man? You say, “Let’s buy him a drink.” And if he says yes, then afterwards your friend would say, “Why did I buy this person a drink? I must be interested in him.”

Another approach, of course, is to help the guy play hard to get. So you know the phenomenon of cognitive dissonance? In the original experiment, social psychologist Leon Festinger got people to screw bolts into boards for a very long time. He pays some of them very little, $1, and he pays some of them a lot, $20. And then each group was asked how much they like it, whether they would recommend it to another friend and so on. Now, the people who got paid $20 said, “The task was boring, I got paid a lot, that’s fine.” The people who got $1 said, “The task was boring, but I got paid a dollar. So why did I do it?”

You can’t change what you’ve done — you can’t change the fact that you did it for an hour. It creates a dissonance: “I did it for an hour for no money, how can that be?” And then they said, “It must mean that the task is quite interesting.” Therefore, they elevated their understanding of how interesting it was to justify their actions.

Kristen Doerer: So that’s the same thing with people to a degree.

Dan Ariely: That’s right. So if somebody plays hard to get, at some point you say to yourself, “How do I feel about them? Look at me, I’ve been chasing them for such a long time, I must really love them.”

And another thing, another direction — all of this depends on how meddling you want to be — we often don’t know the causes of our emotions. There’s an old question in psychology: Do we run because we’re afraid, or are we afraid because we run? So imagine that you’re in the jungle and you see a lion, and you start running. Did you first have fear, and then you started running? Or was your running so instinctual that you started running, and then you asked yourself, “Why am I running? I must be afraid.” There’s actually quite a lot of evidence that our interpretation of our emotions comes later. So if you want to be meddling, you can ask yourself: how can I create an emotional state in my friend and get your friend to feel that this is because of the guy?

Kristen Doerer: That is pretty clever.

Dan Ariely: So you could get them tipsy, you can get them some spicy food so their tongues will sweat, you could take them to a frightening movie or on a roller coaster, and they think “Oh, it must be because I’m really excited about this guy.” You can do all kinds of things to create an emotional state, and as long as they will attribute it to this other guy, that would help.

Relationships in a world with so many options

Kristen Doerer: To go back to that what you were saying about how it pays to play hard to get, my question for you is, in a world with so many options — think about Tinder, online dating or just in general — people tend to lose interest very quickly. So does it still work to the same degree when you have this saturation?

Dan Ariely: This world in which we have so many outside options is certainly not an easy world. Let’s say you wake up next to your significant other every day, you look at them and you open Tinder at the same time. You see the good things in the person next to you, but you also see the bad things. You’ve seen them wake up with morning breath, and they don’t always put the toilet seat up, etc. But the people on Tinder are kind of perfect, right? So when you’re dealing with somebody whose flesh and blood next to you, you see more of their wrinkles.

So I think as long as you’re dating somebody and you keep the half an eye open for others, this is really a problem. Because you’ll keep on asking yourself all the time: Is this good enough? And when you go on online dating, humanity looks amazing; everybody’s so wonderful and thoughtful and loves poetry and running and hiking. I think if you date and still remain online at the same time, that’s a really bad recipe for success.

There’s a beautiful paper by Dan Gilbert about this. In this experiment, people learn how to shoot film, pictures. And one group, they say, “Hey, pick the picture you like the most, we’ll send it to England to be developed and we’ll get it back to you in two weeks.” And people picked their favorites and they tell them they sent them to England and two weeks later they give them the big pictures and ask, “How much do you like it?” Another group did the same thing, but researchers say, “We’re sending it to England to develop it, but in two weeks when you get it you could decide to change your mind.” Two weeks later when they give them the picture, nobody wants to change their mind, but when they ask them how much they like the picture, they like it less.

Why? Because the first group of people said this is my picture, let me kind of learn how to deal with it. I’ll just focus on how wonderful it is. The other people kept on asking themselves, “Do I really like this?” And this is kind of the Tinder world in which you’re dating one person but you keep on asking yourself do I want to date another person? From that perspective, the world of arranged marriages has some advantages.

I’m not recommending we go back to this, but we do need to recognize that the freedom to change our mind all the time is also lack of commitment. So imagine that you woke every morning next to your significant other, and imagine that your relationship was one day at a time. Every morning you wake up, you look at each other in the eyes and say, “What do you say, another day? Yes, no?” In this kind of relationship, how much would you invest in the other person?

Kristen Doerer: Not a lot.

Dan Ariely: That’s right. If you understand that a relationship is a dynamic thing and the quality of the relationship depends on your investment, that means that keeping an eye on Tinder, for example, limits your ability to invest in it.

Back to your question about playing hard to get, I think that playing hard to get is a good strategy. Now, you might lose some people from time to time. But I think that you want to play hard to get continuously, and I don’t mean in a bad way. I think that people need to continuously pursue each other romantically. Taking each other for granted is just death for romance.

Questions you should ask on a first date

Kristen Doerer: In your Google Talk you joked, what really makes a first date interesting is going over each other’s resumes. In other words, people were asking all these bland questions — Where did you go to school? How many siblings do you have? — which don’t really promote any real connection. So I’m curious, if a couple’s on a date, what are three questions that you would suggest they ask each other?

Dan Ariely: So you know these 36 questions that psychologists use? Those are not bad questions. You want questions that get both people to think. If you think about the principles we’ve talked about, you want both people to be engaged, you don’t want one person to just repeat something they know by heart. You want them actually to be thinking about something. Also, if you think about this idea of arousal, asking things that are challenging and interesting and private can actually increase arousal and intimacy. Questions I would ask, for example, is: What was the mistake that you’ve made that you’ve learned the most from in your life? It’s not easy to come up with, it’s likely embarrassing, and it certainly would be interesting for both parties.

Divorce rates and wealth

Kristen Doerer: There was a study that came out about two years ago about divorce rates. According to the study, spending $2,000 to $4,000 dollars on an engagement ring was associated with an increase in the risk of divorce, but then again, the more wealth, the greater likelihood that the couple will stay together. The other thing that the study showed was the bigger the wedding, the less likely a couple will divorce, but the more expensive the wedding, the more likely a couple will divorce.

Dan Ariely: The problem, of course, is those studies are correlational. But let’s talk about weddings for a second. I think a lot about weddings has to do with the contract you have with society. By the way, two people, who read my blog or my books, asked me to officiate their wedding.

Kristen Doerer: Did you do it?

Dan Ariely: Of course. I got ordained for that purpose, I flew to New York and I conducted the wedding. It was great. It gave me some time to think about it from a contract perspective. Think about it, what contract do you sign in front of a lot of people? It’s a wedding. Nothing else. And I think the reason we sign it in front of other people is because we understand it’s not just between two people, it’s across society. And we need the help of a lot of other people to make this work. And I think this element, the more people you include in the wedding, the stronger your social tie is to this wedding. So I think that’s one thing.

The money part is basically the wrong emphasis. The money part is a transactional element. I think even just having the discussions about ring size and cost, it’s not as bad as a prenuptial, but it’s kind of the wrong way to start a relationship.

And if you think about what a prenuptial is, it’s basically a violation of the social contract. You have this contract that says, “You know what, we’re not really going to worry about the details that much. We’re just going to basically go into this agreement with good faith that we’ll worry about each other’s benefit in the long term. And we don’t know exactly how it will work, and things will fluctuate over time, and we can’t even conceive of all the possibilities of where these things will go, but we’ll just make it work.”

But the prenuptial kind of violates that. I think a wedding ring doesn’t violate it necessarily, but the moment you make a wedding ring 3 or 6 months of your salary, it kind of gets into that direction of making it a financial contract rather than a social contract.

Kristen Doerer: And they found a correlation between less wealth divorce rates.

Dan Ariely: Couples with lower incomes are more likely to get divorced, yes.

Kristen Doerer: Is that just because of the stresses that poverty can put on a couple?

Dan Ariely: Absolutely, yes. There was actually a really sad study showing that in the U.S., couples try to move to places with good schools, because they want to give their kids a good education. They basically push their budget trying to move to as good a place as they can to give their kids the best education possible. And in the process, they increase bankruptcy, domestic violence and divorce rates. It’s sad. And you know partly, it is that the American education system, which is funded by local schools, that is creating this terrible incentive. If you’re a parent and you care about your kids, you’re basically going to sacrifice a lot. Financial stress is a huge part of unhappiness in relationships.