Of course, there is a selection bias at work in these raw statistics: the unmarried population includes a disproportionate number of individuals with atypical lifestyles and negative health behaviors. (The exceedingly high figure for male mortality includes binge drinking and reckless driving—what Waite calls “stupid bachelor tricks.”) But even after statistical controls to correct for such distortions, the disparity in health outcomes remains too great to be accounted for by external factors alone.

 

John T. Cacioppo, director of the Center for Cognitive and Social Neuroscience at the University of Chicago, says that, conversely, the practical social support of marriage—having someone to share a healthful meal, remind you to take your medicine, or drive you to the doctor—cannot fully account for the observed health benefits of intimate connection.

 

“Linda Waite’s findings were that marriage at the very least led to a slowing of the declines in health we see with aging,” says Cacioppo, president of the Association for Psychological Science and an advisor to eHarmony’s research team. “When we added the distress of feeling isolated within the marriage into a statistical analysis of our own marriage data, the health benefit disappeared. And as we all know, marriage can also add stress to life. Our data from many different sources suggest that, to a large extent, it’s the subjective experience itself—whether you are socially satisfied or socially distressed—that’s driving health in either a positive or a negative direction.”

 

In the early 1990s, Cacioppo, along with Gary Berntson of Ohio State University, co-founded the discipline of social neuroscience, which incorporates social psychology’s methods of observation and self reports, experimental manipulations, and longitudinal studies, but cross-correlates with extensive analysis of biophysical markers. In addition to blood pressure, stress responses, and immune function, these markers include neuroimaging (fMRI) that reveals specifically which brain area is activated in conjunction with which purported emotional response.

 

“Multivariate, multilevel analysis,” says Gian Gonzaga, who will do much of the hands-on eHarmony research. “It’s like 3-D chess.”

 

In 2001, Cacioppo received a $7.5-million grant from the National Institutes of Aging to study how the social stress of feeling isolated can affect human health. His data suggest that the feeling of protracted emotional isolation (again the subjective experience) contributes to learned helplessness, which leads to passive coping, which leads to higher total peripheral resistance in the cardiovascular system, which over time leads to high blood pressure.

 

One of Cacioppo’s most recent findings is that the distress of emotional disconnection can, in fact, alter gene expression in human leukocytes, the immune system cells that defend against infectious disease. Specifically, this subjective social factor—the feeling of being isolated, not the objective reality—was associated with under-expression of anti-inflammatory glucocorticoid response and over-expression of genes bearing response elements for pro-inflammatory transcription factors. Such inflammation, when prolonged, has been associated with heart disease, arthritis, and even Alzheimer’s.