JENNIFER LUDDEN, host:
This is TALK OF THE NATION. I'm Jennifer Ludden, in Washington. Neal Conan is away.
For years, we've all heard and passed on some common tips for leading a long, healthy life: get married, think happy thoughts, reduce your stress and, of course, exercise a lot.
Well, not so fast. An eight-decade-long study followed the lives of 1,500 boys and girls, and it's debunking some of that advice.
About 20 years ago, health scientists Howard Friedman and Leslie Martin picked up where this study left off. They collected new data and delved into the subjects' social manners, psychological outlook and physical health. Now they've published "The Longevity Project." It finds some intriguing explanations for why some of us are blessed with lengthy, healthy lives and others are not.
So what are you doing to assure your longevity? If you'd like to pick the brains of our guests to see if it might work, give us a call. Our number here in Washington is 800-989-8255. Our email address is firstname.lastname@example.org. And you can join the conversation at our website. Go to npr.org and click on TALK OF THE NATION.
Later in the program, why fewer African-Americans are tying the knot and what it means for black families.
But first, the secrets to a long life. Howard Friedman and Leslie Martin's new book is "The Longevity Project: Surprising Discoveries for Health and Long Life, From the Landmark Eight-Decade Study." They join us now from a studio at the University of California, San Diego.
Nice have you with us.
Dr. LESLIE MARTIN (Co-Author, "The Longevity Project"): Thank you.
Dr. HOWARD FRIEDMAN (Co-Author, "The Longevity Project"): Great to be here.
LUDDEN: Howard, let me ask you first. You know, the bookstores are full of books offering all kinds of advice on how to live longer. What makes yours different?
Dr. FRIEDMAN: Well, everyone knows that some people are more prone to disease and they take longer to recover and they live shorter lives, while their seemingly comparable friends and associates thrive. It's been - there are all kinds of explanations out there. Some of them are genetic factors, of course. Those play a role. But the genes only account for about a third of the variation in how long people live. So we know it's other things that people do, but no one's ever been able to really follow people for a long time to see what causes what.
So what's really unique about our study, it's the first scientific study to follow people from the time they were children, in the 1920s, as they grew up, went to work, got married, had a family, (unintelligible) at around and moved into old age, to see who thrives and lives long and who falters and succumbs before their time.
LUDDEN: As you write in the book, death certificates don't lie.
Dr. FRIEDMAN: That's right. When we have your death certificate, we know your quality of life. So rather than just asking people how healthy you are, we first start with longevity. People who live long lives are people who generally stay healthier throughout their lives. People say, well, I don't care how long - I don't want to live to be a hundred. I just want to live it up now and have a good time, if I - then when I die, I die. Well, you know, there's a problem with that, which is that the people who live the longest are usually the people who stay healthiest and are able to live those fulfilling lives.
So it's really important to look both at how long people live and how healthy they stay. And we do both.
LUDDEN: So, Leslie, as we heard in the introduction a few minutes ago, one of the biggest bombshells you all found is, you know, cheerful and optimistic children, actually less likely to live longer. Tell us a bit about how you saw that play out.
Dr. MARTIN: That was actually one of the really surprising things that we found in "The Longevity Project." We expected, based on many other studies that have been done - and many of them quite good studies - that the most optimistic, cheerful kids with the best sense of humor would live the longest lives. And we actually found the opposite.
One of the things that is explaining what's going on with these kids is that the most cheerful, optimistic kids grew up to take more risks. So by virtue of expecting good things to happen and feeling like nothing bad ever would, they predispose themselves to be heavier drinkers. They tended to be smokers, and their hobbies were riskier.
But over and above that, they also lived their lives somewhat differently, in general, taking a number of different risks. And, you know, they probably didn't have computer hard drives. But if I were to, you know, think about a modern corollary, I would think, you know, these are people that figure, huh. My computer won't crash. No need to back it up. You know, don't need to worry about the speed limit. Don't need to worry too much about anything. And, in fact, some degree of worrying actually is good.
LUDDEN: Okay, that makes me feel better and more worried...
(Soundbite of laughter)
LUDDEN: ...for very different reasons. A little worry, then, is okay.
Dr. FRIEDMAN: In fact, it was really quite surprising. It makes sense when you hear about it, in retrospect. But the prudent, persistent, plan-ful people -both in childhood we measure that, and then in young adulthood we measure that - that was the strongest individual difference or personality predictor of long life. People stayed healthier, and they lived longer.
So it wasn't only because of the kinds of things that Leslie was just talking about. It wasn't just that they avoided certain risks. But they also developed better social relationships, and they did better in their work. They accomplished more. They generally lived a life that, in many different ways, led to them thriving.
Dr. FRIEDMAN: And people sometimes think, oh, well, that sounds really boring. But just the opposite was true. The people who were most responsible and really stuck to the things that they started - they were persistent. They were honest. Because of those qualities, they tended to get nice opportunities in life. And so they went on to live some of the most exciting and interesting lives of anyone in the study.
LUDDEN: You've all used a word, conscientiousness, to describe this personality. You really - you're talking about a personality that is prone to longevity.
Dr. FRIEDMAN: That's right. And it's partly, probably, biologically based. But it's certainly partly learned. And we think of it in terms of prudence and persistence, in particular, but also responsibility, dependability, being plan-ful - the kinds of people you'd want to be heading your organization or your country, or any position that involves responsibility, or even to be your boss, in some ways.
LUDDEN: So you followed these children through their entire lives. Did they stay true to their childhood personalities? Or is there hope for some who may be have been a little footloose and fancy free in their youth? Can we change?
Dr. FRIEDMAN: Well, that - you know, that's a very interesting question. It turns out it's not fixed. It's stable, so it changes only slowly. But we found and we looked at the children who were very conscientious and prudent and persistent when they were young, that some of them became less so as they got older. And some went the opposite. They were really impulsive kids, but as they matured, they became much more conscientious. And that really made a difference.
So it's not something that's written in stone. If you can change - and in the book, we talk a lot about ways people can change and ways they can see where they are on their trajectory. It really made a big difference. And people who became more conscientious as they got older - and we're talking from childhood to the young adulthood - often almost caught up to the people who were conscientious their whole lives.
LUDDEN: Now, you talked about the importance of social networks, and we have heard about that. But you also write that sociability is a double-edge sword. What do you mean, Leslie?
Dr. MARTIN: Well, when we talk about sociability as measured in childhood, we were looking at the kids who like to play with large groups of people, who enjoyed social interactions. Sometimes that was more important to them than other things. Sometimes their teachers described that they were more interested in interacting with their friends, perhaps, than doing their studies.
So we recognize that it is important to have social ties. But the idea of a very sociable, very extroverted social butterfly isn't necessarily important. We found that sociability was neither harmful nor are helpful. It was really kind of a wash. It has some benefits that go along with it, and we'll probably talk more about that in a little bit, with regard to social ties.
But people who are very sociable and interacting a lot oftentimes were sort of pulled in the direction of some-less-then-healthy habits, some less-than-ideal behavior patterns. And that's the other side of that sword.
Dr. FRIEDMAN: And it's important for parents to recognize that. Some parents become upset: Gee, my child's not very extroverted. Well, if they're focused and they're persistent, that turned out to be even better.
LUDDEN: Let's bring some listeners into the conversation. Eric is on the line from Gerber, California.
ERIC: Hi. I have a comment on that. And my comment is, basically, that I follow Bible principles. And I find that that helps me...
LUDDEN: What do you mean, Bible principles?
ERIC: For example, in Proverbs 14:30, it says: A calm heart is the life of the fleshly organism, but jealousy is rottenness to the bone.
So, science has verified that when you're angry, you actually damage yourself, when you get enraged. But if you're calm, it's a lot healthier.
ERIC: And another one is I Timothy 4:8, where it says: Bodily training is beneficial for a little, but Godly devotion is beneficial for all things, as it holds promise for the life now and that which is to come.
So getting physical exercise is definitely promoted by the Bible. But spiritual things are what's going to lead to everlasting life. So that's my point of view.
LUDDEN: All right, Eric. Thanks so much.
So, Leslie and Howard: calm, not jealous, and spiritual exercise. How about that?
Dr. MARTIN: Well, we've hit on a few different things. Actually, this caller has brought up a number of things that we actually did look at in this study. With regard to being calm, we found that some stress is actually also not a bad thing. So when people are doing things that are important to them and that they're committed to - and in particular, we looked at people who had very stressful jobs. When they found meaning in those jobs and they were committed to them, that stress really didn't hurt them. They thrived in spite of or perhaps with the aid of it.
Physical exercise, the caller mentioned, also. And physical exercise, we certainly know that that's good for us. We've known it for a long time, and yet when we look at ourselves now, as a nation - and this is true in many other countries, as well - we're less fit than we have been in the past. So clearly, it's not enough just to know that we should be fit or to try too hard to push ourselves into very contrived and rigorous sorts of exercise regiments.
People who feel that that's really necessary oftentimes start, maybe around New Years, and they have these resolutions. I'm going to log X-number of miles per week. Or I'm going to do this particular workout at the gym, and that's very important and I'm going to stick to it. But people get bored with that, or they just hate it, or sometimes they injure themselves. And so very quickly, we see these sorts of resolutions sort of fall by the wayside, and people go back to their sedentary habits.
What we found in "The Longevity Project" is that physical activity is important, but it doesn't so much matter what you're doing. Getting up out of your chair and consistently, over time, being active is really what's important. And that can be gardening. It can be woodworking. It can be hiking or swimming or tennis. Whatever it is that you love, that's what you're going to continue doing.
LUDDEN: And I loved your finding that it's never - it's not too late. Middle-age is an okay time to start that. Right?
Dr. FREIDMAN: Yeah. That was really one of the major findings, that a lot of the people who were really active in college and college sports teams and so on, they tended to fade out over time. They - by the time they were in their 50's, they were not much different from the people who weren't really active in youth.
But the key was to stay active, or even to become active. So middle-age, if you can pick up some activity you like - it doesn't have to be going to the gym every morning - that really has a big impact on the rest of your life.
And I should say that we're really talking here about the difference between people who become sick and die in their 50's and 60's, versus those who thrive into their 70's, 80's and 90's.
LUDDEN: All right.
Dr. FREIDMAN: So we're not just talking about, you know, really old age.
LUDDEN: We're talking about the secrets to a long life and busting some of the myths about it. The book is "The Longevity Project." What are you doing to assure your longevity? We'll have more calls coming up. Call us at 800-989-8255. Or e-mail us at email@example.com.
I'm Jennifer Ludden. This is TALK OF THE NATION, from NPR News.
(Soundbite of music)
LUDDEN: This TALK OF THE NATION, from NPR News. I'm Jennifer Ludden.
We're talking with Howard Friedman and Leslie Martin, co-authors of the book "The Longevity Project: Surprising Discoveries for Health and Long Life from the Landmark Eight-Decade Study."
What are you doing to assure your longevity? If you'd like to pick the brains of our guests and see if it might work, give us a call. That number is 800-989-8255. The email address: firstname.lastname@example.org. And you can join the conversation at our website. Go to npr.org and click on TALK OF THE NATION.
Let's get another caller in. Esauyo(ph) is in the Huntersville, North Carolina. Go right ahead.
ESAUYO (Caller): Hey. Thank you for picking my call. On top of exercising at least five-and-a-half hours a week and eating right, I try to maintain the mental stimulation as much as possible, like reading books. And also try to read areas of a book that I don't know about, so that I don't get, you know, not just maintain physically healthy, but also mentally healthy so that I don't get dementia.
LUDDEN: All right. Let's see what Howard at Leslie say about that.
Dr. FREIDMAN: Well, generally, we found that people who didn't shy away from their work, got involved in things, people who worked the hardest lived the longest. So if you're increasing your responsibilities at your job, that was a good thing. A lot of times, people shy away from work and say, well, I don't want to take that on. It's going to be too hard. Or like this caller just said, gee, it's going to be hard to go through all those books. But if you set a goal and stick with it, we found that, also, that was a very strong predictor of people who stayed healthy and lived long.
LUDDEN: All right. Thanks so much for that call. Let's get another one in.
Dale in Egg Harbor, Wisconsin. How are you?
DALE (Caller): I am very well, thank you. This is a fascinating subject for me in particular, because my grandfather, my mother's father, lived to be 100 years old. He was 82 years old when I was born. And he was a farmer, among other things. So he was very active, of course. But he was also - he lived in the same house from the time he was about two until he died. He was so thoroughly embedded in his community. And instead of being bored by being in one place, he did so many things. He was a farmer. He was a schoolteacher. He was a lay preacher. He taught me to play chess, and he was 82 years old when I was born.
So he kept his mind sharp, and he was physically active. And his face was important. He really knew who he was, you know, because he was so deeply and firmly placed in the community.
LUDDEN: And you think this his secret to a long life.
DALE: Yeah, I think so. I think all of those things together. But my sense of him was that he never had to think too much about who he was, because of the way he lived in his community and participated in it and did so many different things. It kept him active, kept his mind sharp, and he just had a terrific life, and a long one.
LUDDEN: Dale, thanks so much for the call.
Dr. MARTIN: It's so interesting that this caller mentions this, because we saw, again and again, that social connections and social ties really were important. People who had more contacts, more frequent contacts with friends and family -whether that be through work or other venues - they actually really benefited from that.
The caller also mentioned being engaged in the community. He didn't say specifically exactly what that entails - although being a teacher is certainly one way. But we saw that over and above the number of connections and the frequency of interactions, that when those connections involved helping other people, reaching out, being actively engaged to do things for others, that was an added bonus on top of what we already we see as quite beneficial from the social contacts themselves.
So it doesn't surprise me at all that this caller's grandfather lived a very long life. It sounds like he had a number of mechanisms in place that are exactly the kinds of things that you would want to promote that long life.
Dr. FREIDMAN: One of the interesting things about "The Longevity Project" is that we were able to look back throughout the whole life so that - a lot of people, they want to say, well, what - who lives long, like the caller said. And they looked to people who are quite old and try to ask them for their secrets. But there's a problem with that, because what you really want to know is what those people were like when they were children, when they were in their 20's and 30's and 40's that let them thrive between 80 to - and 100.
So we were able to do that and "The Longevity Project," go back and see what the long-living people were like throughout their lives, step by step. And, in fact, in the book, we have some self-quizzes people can take and find out their own trajectories. Are they heading onto a health - what we call a healthy pathway? Or are there things they should do to get themselves on a healthier pathway?
LUDDEN: And actually, we have one of your quizzes at our website. People can go to npr.org and click and TALK OF THE NATION, and find out if you have a personality print of longevity.
Leslie, I want to ask you about something that you take on here, which is this well-known gender gap, that women always seem to live longer than men. And why did you find that is?
Dr. MARTIN: This was really interesting. We looked to at relative masculinity and femininity in our samples. So this means that relative to other individuals in this particular group of people, how masculine or feminine were your preferences? It's important to note here that we were not looking at risk behaviors, per se. We were looking at the kinds of things that people enjoy doing or thought they would like as an occupation or a hobby.
And using their responses, we scaled them: Are they high or low on masculinity or femininity? And we found that the more masculine individuals - regardless of whether they were men nor women - were at greater risk of early mortality, whereas the more feminine individuals, women and men, actually were protected. So that was really interesting, and part of it did play out in terms of health behaviors.
So we saw that the more masculine women were more likely to smoke and drink and do some of these things that historically have not been the things that women were as likely to do, and so have perhaps protected women, to some degree. But that didn't completely explain what was going on. There really was this femininity that encompassed other things, such as social connections and other elements that was protective, regardless of whether you were a man or a woman.
LUDDEN: When you talk about femininity, are you talking about a personality type again? Or conscientiousness...
Dr. MARTIN: I wouldn't call this a measure of personality type, per se. But it has many similarities, in that it tends to be pretty stable over time. So the more feminine men, they never were the tough guys. Even in childhood, they were a little more sensitive. Their parents and teachers reported them as caring a bit more about what other people thought than the more masculine kids. So you see this sort of pattern that's relatively stable, but, again, something that's can be changed.
You can reach out and strengthen social connections. You can look at your health behaviors and, you know, make some modifications to your trajectory.
LUDDEN: All right, let's take a call.
Cole in Sarasota, Florida. Welcome to TALK OF THE NATION.
COLE (Caller): Hi. I've got a questions. There's an old adage that goes, you know, you can have vices, but everything in moderation. I was wondering if your study reflected that moderate smokers and moderate drinkers who weren't heavy users had the same kind of early mortality as the heavy users? Or was it closer to non-users, as far as that was concerned?
Dr. FREIDMAN: We did look at that, and no. Sorry.
(Soundbite of laughter)
Dr. FREIDMAN: The people who smoked, it didn't - you know, the more you smoke, the worse it was, and the same thing with drinking. There is some other research that suggests very moderate drinking, maybe one day drink a day, can be part protective. But we didn't find that.
Basically, the people who are more likely to smoke and they're more likely to drink and who are more likely to get engaged in other habits that we would usually call unhealthy, they faced illness and they faced earlier death.
LUDDEN: Okay, sorry, Cole. Thanks for calling.
(Soundbite of laughter)
LUDDEN: There's an emailer here. Brook in Greensboro, North Carolina, says: I've enjoyed a lot of health benefits since I adopted a vegan diet, including weight loss, increased energy, and a noticeable improvement in rheumatoid arthritis symptoms. Are there any good studies on the relationship between veganism and longevity? And since you all looked at people who were born in -was it 1921?
Dr. FREIDMAN: Yes.
LUDDEN: You may not have interviewed many vegans in this.
Dr. FREIDMAN: No. Outside of our research, there is pretty good research suggesting that people who eat more of a plant-based diet stay healthier. But those are the kinds of things that everybody knows about. You know, don't eat too much fats and red meat, and go to the gym and don't smoke. And we hear that again and again.
What's really interesting about "The Longevity Project" is we found ways to do that. So if you want to eat healthier, we found you should just be associating with healthier people. And that's something that people really don't usually think about. They think - they make a list. Today, I'm going to - now I'm only going to eat these things this week. And then, you know, their friends say, oh, come on. Let's go eat these unhealthy foods. Or let's go do this unhealthy kind of behavior.
So we found that people who wanted to get themselves on a healthier life path, they started associating with healthier people. So look around, look at your friends, look at your family...
(Soundbite of laughter)
Dr. FREIDMAN: ... look at your co-workers and...
LUDDEN: Find your coworker eating a big salad for lunch.
Dr. FREIDMAN: Right. The best way to do that is to make those people your friends, and then naturally and painlessly, you become healthier.
LUDDEN: All right. Alex in Richmond, Virginia writes that she or he - sorry -who wants to hear about the disastrous lives. It seems like some people just have it coming. What did you learn from the, quote, "bad examples?" And are some people just cursed?
Dr. FREIDMAN: Well, that was one of the very interesting findings. That's a great question, because we found that it wasn't random who had bad things happen to them. People always think that, well, you know, that - just unlucky. You had stress. You had traumatic things have been. Certainly, sometimes that's happened. Things are random.
But a really important lesson of "The Longevity Project" is that people often make their own good or bad luck. We found that people who started out on the right path, they had less stress happen to them. They had better things happen to them, and other people, they did. There was a kind of disaster-prone person who - they just went from one bad luck kind of thing to another.
And we can't really summarize it in a minute, but in the book, we do explain -we trace people's lives and show how they bring good things or bad things on each other. So, you know, people probably are skeptical of that, but it's really a good question that person sent in.
LUDDEN: What are you doing to try and live longer? Call us at 800-989-8255.
Leslie, you talked about a way of thinking that you call - am I pronouncing it - catastrophizing, thinking about catastrophes.
Dr. MARTIN: Yes. That's correct.
LUDDEN: Tell us about that.
Dr. MARTIN: A catastrophizer is someone who sees everything that goes wrong as a real catastrophe. We think of this variable in terms of explanatory style, so what the...
Dr. MARTIN: ...(unintelligible). Well, kind of. The research out there shows that when you're explaining good things that happen to you, it's not as important how you explain them. But when bad things happen, how you explain them and understand them and think about them can be quite important. And whether you see them as a really big deal seems to be the most important component.
And we had some people in our sample who, when bad things happened or when they described characteristics about themselves that maybe weren't the greatest characteristics or maybe weren't the best, most enjoyable events, they went way beyond that in their explanation. And they really felt that this was a pervasive life-changing, you know, unfixable, huge problem. And that really boded poorly for them.
LUDDEN: So it kind of sounds like it's a - you're kind of creating your own...
(Soundbite of laughter)
LUDDEN: ...trajectory there just by your consciousness.
Dr. MARTIN: You're exactly right. These individuals when we looked at what - so we saw that they were on average at greater risk for early mortality. And when we looked at what they were dying from, although they were pretty comparable to the non-catastrophizers on cardiovascular disease and cancer and some of those, they were dying at higher rates from the accidents and injuries. So this included certainly suicides but also some other things that may have been suicides or may have simply been very reckless behavior driven by the sense that things were really bad anyway, and it didn't matter anymore.
LUDDEN: All right. You're listening to TALK OF THE NATION from NPR News.
Abdulla(ph) is on the line. Are you really calling from Saudi Arabia?
ABDULLA (Caller): Yes.
LUDDEN: Hi there. Welcome.
ABDULLA: Thank you for having me on the air. I meet here in Middle East people who live in the desert, and I find a guy like in his 80s, and he tells me his father is still alive. He's 110, and he's in whatever, in the tent or in their compound. And I hear stories people in the (unintelligible) mountains live up to hundred. A guy like was in the local people last year reached 150. It's very also normal for people to still have active life beyond a hundred.
And these people don't go to hospitals. They don't take aspirin. They don't diet. They have their own diet, but they actually have no medications. Of course, they don't go to McDonald's and pizza...
ABDULLA: ...but I was wondering if this is genetic or because of their lifestyle, living as herdsmen. And maybe this is a dying breed of people since new people are no longer traditional. So you like to hear your explanation for that.
LUDDEN: Very interesting. Howard.
Dr. FRIEDMAN: Well, again, in general, only about a third of the variation or maybe less of how long people live is due to their genes. It's certainly important, but it's not everything.
The people on our sample and people in the United States, it's very unusual to have a man live over a hundred. It's a very tiny minority. So maybe we'll have to come to Saudi Arabia and see...
(Soundbite of laughter)
Dr. FRIEDMAN: ...what's going on there because we don't know that but I - you know, it's - certainly, in some places in the world, people do tend to live longer, but the key is not to look at the old people. Again, the key is to go back and see, well, what were they like when they were younger? And that's what "The Longevity Project" can do.
LUDDEN: Abdulla, thanks...
Dr. MARTIN: And...
LUDDEN: ...for the call.
Go ahead, Leslie.
Dr. MARTIN: I just want to add in there too. Just in thinking of what he described, though, it does sound like a pretty healthy lifestyle in terms of many of the things that we looked at, you know, the physical activities, the hard work, the closeness with family in, you know, in that family group. So there may be components there probably of a pretty healthy diet that may contribute in addition to genetics and who knows what else.
LUDDEN: You also do write, though, that in your estimation, modern medicine hasn't contributed to longevity as much as we might think.
Dr. FRIEDMAN: Yeah. That's a very interesting point, I think, that people should be more aware of. We tend to think that people are living so much longer now because of medical interventions late in life, but, in fact, that's not really the case. Most of the advances in longevity have been preventing infant mortality and childhood diseases and childhood mortality and accidents.
And, in fact, in the United States, a 60-year-old white man now is only expected to live maybe two or three years longer than his father or his grandfather. So there hasn't been a huge increase at the - in the end of life.
That's what's real interesting about "The Longevity Project," because medicine, obviously, if you're sick, sometimes, there's miraculous cures. But, in general, a medical intervention is seen as successful if it extends life on average a year or two years, and many of them only have average help of a few months.
LUDDEN: All right.
Dr. FRIEDMAN: But the kinds of factors we're talking about that affect people for their whole lives, the steps you take, they accumulate. So if you put together all the kinds of factors that we're talking about, you're really talking about five years and maybe even 10 years in increased longevity. And that's way beyond what end-of-life medical interventions can do. And it probably could lead to lower costs as well, so it becomes relevant to the national health care discussions.
LUDDEN: All right. You do note that there were some limitations of this study. This study focused on very promising middle class kids, so it's not a, you know, wide ranging for every group, but lots of fodder for thought there.
Thank you both so much.
Howard Friedman is distinguished professor of psychology at the University of California, Riverside. Leslie Martin, professor of psychology at La Sierra University and a research psychologist at the University of California, Riverside. Their latest book is "The Longevity Project: Surprising Discoveries for Health and Long Life from the Landmark Eight Decade Study." You can find an excerpt from the book a take that quiz on longevity at our website. Go to npr.org and click on TALK OF THE NATION.
Leslie and Howard joined us from a studio at the University of California, San Diego.
Thank you so much.
Dr. MARTIN: Thank you for having us.
Dr. FRIEDMAN: Our pleasure.
LUDDEN: Coming up, why fewer African-Americans are choosing to tie the knot and what that might mean for black families. I'm Jennifer Ludden. This is TALK OF THE NATION from NPR News.