RESEARCH LINKING CONSCIENTIOUSNESS AND LONGEVITY
One of the most powerful studies explaining the impact of conscientiousness on human development came about through an extensive research project that began in 1921. The study lasted 80 years, and it culminated in a fascinating and comprehensive book titled The Longevity Project by Howard S. Friedman, Ph.D., and Leslie R. Martin, Ph.D.
In this chapter, I present some of the main highlights from Friedman and Martin’s book, because their findings clearly make a compelling case for conscientiousness. In order to be truly healthy and have a long, happy life, you have to have conscientiousness. The Longevity Project study concluded that conscientiousness is the single greatest factor for health and longevity. Incidentally, genes influence your health by only 25 percent.
As you will see here, many factors determine spontaneous conscientiousness. For example, having two married parents is the basic foundation; women are often more likely to have the conscientious personality trait than men; and, even though longevity is far less important than health, both longevity and health are affected by the same experiences.
You see, even if you live a conscientious life, like my beloved wife, that still isn’t enough to avoid suffering from some diseases that shorten it. Two days after I finished reading Friedman and Martin’s book, my wife of 52 years died. An agonizing 13-month battle ended. I decided then to devote my life to studying, teaching, and motivating others about conscientiousness.
I had already spent my whole career helping people overcome pain and depression. I saw time and time again that the real problem for at least 75 percent of people I treated was that they lacked healthy habits, and this was primarily due to poor self-esteem.
It was tremendously exciting for me to find another missing link in this puzzle in 2011 when I dug into The Longevity Project findings. It introduced me to the next logical step in my own research, and since then my efforts have been focused on exploring the field of conscientiousness and, specifically, conscientious psychology. So let me speak now about Friedman and Martin’s findings, and you can see for yourself the powerful impact conscientiousness can have in your own life.
Studying the Impact of Conscientiousness on Human Development
The Longevity Project was an extensive and ambitious research project established in 1921 by Dr. Lewis Terman, who was an American psychologist and a noted pioneer in educational psychology in the early 20th century. Dr. Terman asked teachers to pick their “brightest” students, and just over 1,500 boys and girls, who were born around 1910, were selected for this 80-year-long study. Several groups of research scientists have since continued the work after Dr. Terman died in 1956.
The project concluded with the publication of the book I’ve just mentioned above: The Longevity Project: Surprising Discoveries for Health and Long Life from the Landmark Eight-Decade Study. I discovered this book through reading a review one day in the New York Times and was fascinated to read more.
Friedman and Martin’s findings—the culmination of following the lives of these children, and eventually adults, for some 80 years—shed light on what truly contributes to a long and healthy life. Here are only two of the authors’ conclusions: “Eating slowly doesn’t much matter,” and “Lying about your age and your health does indeed represent a challenge to health researchers.”
The authors also proved that—surprise, surprise—people who live to ripe, old ages do so because they outlive most serious illnesses. Throughout their lives, the subjects who did live to the oldest ages tended to be happier than those who ended up dying younger. And, incidentally, the ones who lived longest also tended to be healthier.
Since, presumably, all people want to live happy and healthy lives well into their senior years and be physically sound and mentally alert right up to the end, do you know what else made the difference? Persistence and prudence.
These just happen to be two of the greatest qualities of conscientiousness and, therefore, the study proved that conscientiousness, when measured in childhood, is the best predictor of longevity. It is also the best personality predictor for long life when measured in adulthood. Related major qualities of conscientious people, such as thrift, being detail oriented, and living responsibly, were all seen to contribute to individuals leading longer and healthier lives.
As it turned out, by the year 2000, 70 percent of the women and 51 percent of the men who were determined to be conscientious in this study had died. The deceased were all born about 90 years earlier; however, it is important to note that the less conscientious of them died much earlier.
The reason for this is that conscientious people do more to protect their health. They engage in fewer risky activities. They’re less likely to smoke, less likely to drink excessively, less likely to do drugs, and less likely to drive too fast. Conscientious people tend to take more safety precautions and are more likely to wear seat belts.
Friedman and Martin concluded that people are biologically predisposed to be both healthier and more conscientious. Furthermore, the researchers stated that serotonin is necessary “to regulate many health-relevant processes throughout the body, including how much you eat and how well you sleep.” I knew from my research that individuals with low serotonin levels are more impulsive, and low serotonin is a major foundation of depression. I found this very interesting, because low levels of oxytocin are another cause of low self-esteem. There is indeed a strong relationship between oxytocin and serotonin.
The Many Benefits of Living a Conscientious Life
Interestingly, conscientious people tend to seek healthier situations and relationships. They have happier marriages, better friendships, and healthier work situations. Friedman and Martin emphasized that these individuals make adjustments to their lives as others do, but they take smaller, more incremental steps—they avoid rapid and sudden changes.
On the other hand, the authors concluded that those who are less conscientious are more likely to be clinically depressed, feel anxious, smoke cigarettes, and have high blood pressure and sciatica—and also have tuberculosis, diabetes, joint problems, and strokes. While it was believed that these people can still lead exciting and very rewarding lives, nonetheless they may not feel as good as they could. As an active physician for 40-plus years, most of my clinical practice involved patients who needed help managing these exact problems.
Apparently, being an extrovert and sociable by itself does not necessarily increase longevity. This was something I knew from my own experience, but it was interesting to see it confirmed. Friedman and Martin approached it through looking at the personalities of scientists and engineers, who tend to be polar opposites of businessmen and lawyers in their abilities, occupational interests, and social behaviors. But generally speaking, scientists outlived nonscientists. The findings in The Longevity Project concluded that only two-thirds of nonscientists reached age 70, but almost three-quarters of scientists did so, too.
Scientists in general tend to be less sociable than lawyers, businesspeople, and salespeople. Overall, the two groups are about equal in conscientiousness, but scientists tended to have long-lasting marriages and more stable jobs where they worked responsibly. In contrast, nonscientists tended to have more tumultuous, less stable, and more health-damaging careers and behaviors. So sociability did not make someone healthier and allow them to live longer—or cause them to be conscientious in and of itself; it had to do with these other factors.
However, the authors did say that individuals who as children were more sociable and extroverted tended to drink and smoke more. In my experience with more than 30,000 depressed people (the majority of whom were introverts), I found that those who became invalids were the ones who were much more likely to be introverts and that they were far more likely to smoke than the extroverts.
Nonetheless, the authors state that length of life is the single best measure of health, and that cheerful and optimistic children are less likely to live to an old age than their more staid and sober counterparts. That’s because overly cheerful children engaged in riskier hobbies and paid less conscious attention to their health.
The Effects of Conscientiousness Developed During Adulthood
Friedman and Martin emphasized repeatedly that adopting healthy habits, such as watching less TV, improving social relations, increasing activity, and helping others, was not as important as having these qualities innately. But it is entirely possible to develop increasing conscientiousness and even extroversion! I am a perfect example of someone who was strongly introverted until age 19 when I entered medical school. I intuited that I needed to become an extrovert, played the role for a few years, and have been extroverted for the past 60 years while remaining conscientious.
Conscientious people are also far less likely to be “catastrophizers” (otherwise known as people who make a mountain out of a molehill). Research has shown that those individuals—especially men—tend to die sooner. Catastrophizers are more likely to die from accidents or violence. During interviews with older men (those in the longevity study who lived until over the age of 70), not one of them ever spoke the word death in reference to his own inevitable demise.
Another interesting study illustrates this same point quite well. Individuals were given propranolol (a drug used to treat hypertension, anxiety, and panic) or a placebo, and the conscientious people were much more likely to survive whether they took the placebo or the drug. In other words, the conscientiousness of taking it was more important than ingesting the drug itself! I fully understand this happening, because I have seen this result more than once myself, where the conscientiousness of taking the medicine had a greater impact than whether the subject got the placebo or the drug.
In The Longevity Project, Friedman and Martin spoke often about the fact that the patterns of behavior in early childhood are far more important than any other single indicator of health. Although breast-feeding may have other benefits, they determined that it did not appear to affect personality. They did find, however, that a greater number of study participants who began school at a very early age encountered more difficulty throughout life and led shorter lives. Children who started first grade at age five were at a much higher risk of dying early than those who started at age six. Incidentally, I am happy to report personally being an exception to this finding and am still with you at age 80 to tell this story!
The Impact of Parental Divorce
You might expect individuals who have more education to live longer and healthier lives; however, the level of education by itself did not seem to be a good predictor of health or longevity. While society places huge value on getting the proper education, there was another life experience that was far more of a factor in the equation than what these children learned in school.
It turns out that one of the most critical life experiences these young people had to deal with was parental divorce. More than one-third of the Terman group faced either death of a mother or father or divorce of their parents. Death itself did not seem to impact the life span of that son or daughter, but “[t]he long-term health effects of parental divorce were often devastating—it was indeed a risky circumstance that changed the pathways of many of the young Terman participants.”
I have found this to be true in so many cases within my clinical work that I was very much interested in these actual findings. In general, the final report concluded that “[c]hildren from divorced families died almost five years earlier on average than children from intact families.” Parental divorce during childhood was “the single strongest social predictor of early death, many years into the future.”
On the other hand, early childhood personality and the effects of parental divorce did not seem related. This is because there were many other independent factors that contributed to health, such as, for example, men were more likely than women to die early of accidents or of violence if their parents had divorced. In other words, they became more reckless.
Among other things, The Longevity Project showed that both boys and girls in divorced families had less long-term education. These children were more likely to engage in drinking and smoking—especially smoking—and women from broken homes were more than twice as likely to be heavy smokers. Sons and daughters from these households also had an increased risk of cancer, and they were much more likely to get divorced themselves.
The study also stressed what has been commonly accepted for a long time: Married men live longer. Divorced men have a much higher mortality risk, and less than one-third of divorced men reached age 70. However, the study also showed that married women did not necessarily live longer. Women who divorced their husbands and stayed single lived almost as long as steadily married women. This agrees with what I have seen in my clinical practice as well—that divorce is much less harmful to women’s health than it is to men’s.
From The Longevity Project, the women who grew up with parents who remained married were also less likely to become divorced. In terms of conscientiousness, the authors found that “folks who later became consistently married individuals had been more conscientious as children.” In other words, prudence and responsibility as a child was more likely to lead to a successful marriage and longer life.
The Role of Exercise in Health and Longevity
With regard to exercise, The Longevity Project also concluded that “being active in middle age was most important to health and longevity.” In other words, being inactive during childhood did not hinder health and longevity if the individual became more active as he or she aged. This I definitely agree with. Time and time again, I have seen adults of all ages overcome pain and depression more quickly and more consistently when they began to exercise in a conscientious way, regardless of early patterns.
On the flip side, The Longevity Project also showed that those who were active as children were more likely to remain active. However, if they became inactive as adults, then the protection of physical activity vanished. Friedman and Martin really emphasized that moderate exercise is significantly more important than running marathons or other vigorous, prolonged exercising.
Tracing the Impact on Career Progress and Success
Of the men in the Terman study, about 20 percent were considered highly successful and 20 percent unsuccessful. Sixty percent were in between successful and unsuccessful. What is important is that those who had the greatest success in their careers were less likely to die young. Put another way, the most successful men lived five years longer than the least successful.
The researchers stated it this way: “[A]mbition, coupled with perseverance, impulse control, and high motivation, was not only good for achievement but was part of the package of a resilient work life.” Both work and family were the most important aspects for health and longevity for men. Males who worked more stressful jobs died younger, as you might expect.
But being happy in those stressful jobs doesn’t necessarily matter for longevity. They say that a man’s productive orientation means more to him than his social relationships or worrying about being personally happy. As with everything else, prudence, dependability, and perseverance seem to be real keys—conscientiousness wins again!
The Power of Actively Working Through Pain
There is a huge difference between chronic-pain patients who become invalids and those who continue to live their lives actively despite pain or even physical disability. Actor Christopher Reeve and well-known author and theoretical physicist Stephen Hawking are two examples of extraordinarily productive individuals despite both having some of the worst possible disabilities. Reeve became a quadriplegic after being thrown from a horse, and Hawking developed a motor neuron disease related to amyotrophic lateral sclerosis (ALS). I have found that individuals such as Reeve and Hawking, who really enjoy their work, rarely become invalids even when they have ongoing pain.
In comparison, a study from the 1970s showed that those who had preexisting personality problems, as suggested by the Minnesota Multiphasic Personality Inventory (MMPI), were far more likely to have chronic pain and disability after back surgery. And another study proved that smokers were nine times less likely to improve after back surgery than nonsmokers!
In fact, 75 percent of my chronic-pain patients had elevated scores on hysteria, depression, and hypochondriasis, and another 15 percent had elevated scores on even more serious personality traits, such as schizoid behavior, paranoia, and so on. After four or five years of routinely doing MMPI evaluations on all of my chronic-pain patients, I stopped, because it is so difficult to discuss such undesirable traits!
Instead, I started using the California Psychological Inventory (CPI), which measures 18 variables such as dominance, capacity for status, sociability, self-acceptance, independence, empathy, responsibility, socialization, and self-control. The traits measured by the CPI tool are remarkably important in evaluating conscientiousness, and I found it much easier to discuss excess or deficient behavior in any of them with my patients.
I also found out that chronic-pain patients who had become invalids had an average of 49 symptoms on my Total Symptom index, but to give you some perspective, anyone with 30 or more symptoms is highly stressed or terminally ill! (My patients have not generally been terminally ill.) Furthermore, on a Total Life Stress (TLS) test, my patients tended to average a score of 75 or above, and higher than 25 on the TLS is enough to increase the number of overall symptoms. In fact, my typical patient had an average of five significant diagnoses in addition to chronic pain. Clearly, people who have great stress also have a wide range of symptoms!
Spirituality, Social Networks, and Doing Good for Others
From these findings in my own practice, I determined that one of the best ways to alleviate pain was to get rid of stress. I also knew that, within the clinic, a good way to bring stress down was to get people more socially engaged—basically, encourage them to make friends and do things for others.
Therefore, I was very interested to read that The Longevity Project researchers also included a study of social engagement and the place of religion as factors that had an effect on health and longevity. They concluded that religiosity did not matter much for men, but it did for women. They also found that it wasn’t religion itself, but rather other personality aspects that were more significant to women. The real importance of religion seemed to be in the activity of social networking—attending ceremonies, participating in community-welfare activities, and being involved in other various church functions.
In contrast, researchers found that for the men, their family and career were far more essential than religion. It was actually family and career social engagement that were more vital to them. In other words, the most crucial effects on health and longevity for both men and women appeared to be the frequency with which they visited and communicated with relatives, friends, and neighbors, and that they participated in community service and found satisfaction with friendships and social contacts.
Other important factors for both sexes included the number of intimate and companionate bonds they enjoyed with others, the quality of the relationships they had with family and close relatives, and how often they attended meetings with social or community groups.
This last point—participation in social or community groups—turned out to be perhaps the most fundamental of all. The authors continued their report by saying that although other studies have shown that those who feel loved and cared for will claim a better sense of well-being, they did not find that this helped much for living a longer life. But having a large social network mattered tremendously—even more so than playing with pets. Over and over, the participants emphasized that helping, advising, and caring for others were among the most powerful factors for men and women in leading longer and healthier lives.
I totally agree—and have seen this proven many times in my practice. People with chronic pain reported to me that just about every time they were asked what their desire to get better was, they said that they wanted to be able to help others. I believe that doing good for our fellow human beings is one of our most natural inclinations, and when an individual is wracked with pain or suffering from depression, he or she misses out on fulfilling this vital need. I find it telling, and very true, that according to Friedman and Martin, “[S]ocial relations should be the first place to look for improving health and longevity.”
The Nonimpact of Modern Medical Advances on Longevity
Many people believe that physicians and their research are extending the human life span. However, The Longevity Project proved a point that I personally have always believed, namely that modern medical cures have actually played a relatively minor role in increasing the overall length of our lives. I know this is something that most people do not understand fully, but it’s true. In fact, the average life expectancy of a 60-year-old white male in the United States has increased only 4 or 5 years during the past 50.
In the words of the Longevity authors, “It is a great misconception (with serious implications) in our society that modern medicine has led to huge increases in the longevity of American adults.” Many other researchers concur with this finding, including Dr. Thomas McKeown in his book The Role of Medicine, which emphasized the fact that 92 percent of the increased longevity in the 20th century had nothing at all to do with medical advances. Furthermore, hundreds of articles, some even published in the Journal of the American Medical Association, listed the medical system itself as the third leading cause of death. Meanwhile, several others have said medical intervention is, by far, the number one cause of death!
Of course, as one might expect, depression, hostility, and aggressiveness all carry risks of a wide variety of illnesses, as well as shortened life expectancy. Friedman and Martin concluded that individual health depends on social health, and they also stated that “[r]esilience was not a trait they were born with, nor an inner insight, but a process of perseverance and hard work.”
They also suggested that long life is associated with “an active pursuit of goals, a deep satisfaction of life, and a strong sense of accomplishment.” They believe that you cannot predict how healthy you’ll be or how long you’ll live based on your parents’ lives. It appears that the most important thing we can do to help people is to aid them in developing healthy social patterns and “inter-activity.”
These findings certainly back up in a compelling way what I have always known: Conscientious people live longer and healthier lives because they take responsibility for themselves and for their actions each day. Simply put, they make sound choices. This was the premise for my own Ph.D. thesis in 1976 and the impetus for my best-selling book that came out of that research titled 90 Days to Self-Health. Now my passion is to help everyone enjoy health and longevity through the power of conscientious living!