Institute For The Future

What a New Measure of Sensitivity Suggests about Future Health Interventions

Alix Spigel had a typically fascinating story on NPR examining new research exploring whether being especially sensitive to environmental influences can worsen the affects of poverty over the long run. It's one of several recent signals pointing to the idea that understanding sensitivity--to environments, to messages, to making changes in our lives--could reshape how we understand and time health interventions. Describing the research, Spigel notes:

On the screen, circles of gently colored shapes flickered and music softly played while a sensor taped to the baby's chest recorded how much the baby's heart beat when the baby breathed in, and how much the baby's heart beat when it breathed out. This simple measure has a complicated scientific name that sounds vaguely like a disease — baseline respiratory sinus arrhythmia — but the researchers were interested in it because it can tell you something about how a baby responds to the world around it. You see, while there's always a difference between how much the heart beats when a person inhales and when he or she exhales, everyone has a different set point. Sometimes there's a big difference, and sometimes it's small. And in very young babies, researchers have noticed that there are different temperaments associated with these different set points. ... Babies with a high set point seem to have a more sensitive nervous system, which makes them more sensitive to their environment, in both good and bad ways. Babies with a low set point seem to have a less sensitive nervous system, which makes them less sensitive to their environment.

And much later in the piece, Spigel sums up the implications of this research:

When the researchers looked at how a child's behavioral problems correlated with the early measurement, the researchers found that kids with high set points were significantly more sensitive to the environment they grew up in than the children with the low set points. If the baby had a high set point and an insecure attachment to his or her mother, the child's later behavior was often deeply troubled. These were by far the worst of all of the kids. But if the child had a high set point and a secure attachment, "those were the kids that were doing the best — the absolute best — of all of the kids in our sample, and they had far and away the lowest reported problem behaviors," Measelle says. The children with low set points were not as good or as bad, no matter their parenting.

This is reminiscent of research we've been tracking for several years now emerging from the field of epigenetics suggesting something very similar: Namely that being sensitive to environments, both social and physical, is itself a kind of genetic marker that influences health, education and a variety of other outcomes.

And critically, being sensitive isn't bad, per se. As Spigel noted--echoed in a great Atlantic piece from several years ago, being sensitive to the environments helps children be healthier--provided they're exposed to healthy conditions.

What particularly intrigues me about this kind of research is that it points toward new ways to measure risk--and, perhaps more importantly, time interventions to reach us at points where we're most sensitive.

And here, it's useful to take a bit of a detour to a seemingly unrelated concept: Habit design. Popularized, most notable, by New York Times author Charles Duhigg in his book The Power of Habit, habit design is beginning to emerge as a strategy in health behavior change efforts. Duhigg gained a fair amount of attention last year for popularizing this idea in a story about how the retailer Target tries to identify pregnant women:

Most shoppers don’t buy everything they need at one store. Instead, they buy groceries at the grocery store and toys at the toy store, and they visit Target only when they need certain items they associate with Target — cleaning supplies, say, or new socks or a six-month supply of toilet paper. But Target sells everything from milk to stuffed animals to lawn furniture to electronics, so one of the company’s primary goals is convincing customers that the only store they need is Target. But it’s a tough message to get across, even with the most ingenious ad campaigns, because once consumers’ shopping habits are ingrained, it’s incredibly difficult to change them. There are, however, some brief periods in a person’s life when old routines fall apart and buying habits are suddenly in flux. One of those moments — the moment, really — is right around the birth of a child, when parents are exhausted and overwhelmed and their shopping patterns and brand loyalties are up for grabs.

The basic idea in heath is something similar: To identify points where we're particularly sensitive and open to messages and efforts to do things differently, and to use that sensitivity to time changes that will help people develop healthy habits. In other words, our sensitive points--not just as infants, but throughout our lives--have an outsized influence on the trajectory of our lives.

Which is why, I think, Spigel's conclusion about infant sensitivity is accurate, but may be a bit too narrow. At the end of her piece, she notes that "researchers hope that this simple measure of a baby's breathing and heart rate might one day be used to flag children," which, of course, it might be. But there's a broader point: Understanding sensitive points--both when we're most at risk and most open to receiving help that will improve our health--may not be a one time measure of childhood, but an ongoing measure that is increasingly important to how we understand our health.