How to Objectively Measure Subjective Feelings

I just got off the phone with Carl Craver, a smart philosopher of neuroscience (yes, redundant) at Wash U in St. Louis. I had some vague ideas about brains and happiness and I wanted to talk to somebody who not only understands brains, but philosophy of science, and so forth. In trying to formulate one of my vague ideas to Carl, I think I semi-successfully clarified something worthwhile to myself. It's not what I was trying to clarify, but I'll take it! Thanks, Carl!

So . . . here's a datum that needs explaining:

Self-reported happiness is stable over the past 50 years–the percentages of the population reporting themselves in each category has not shifted significantly.

Here are two hypotheses that account for this fact:

(1) Adaptation, aspiration, and/or social comparison affect the real qualitative feel of subjective states, such that the way people feel now (in the various categories in the distribution) is essentially the same as the way people felt fifty years ago.

(2) Adaptation, aspiration, and/or social comparison affect the way people report
the way they feel, such that the percentages of people who say they feel “very happy,” etc. remain pretty constant, although the real qualitative feel of their subjective states now (in the various categories in the distribution) is not essentially the same as it was fifty years ago. More people are in fact happier now, but the reporting mechanisms keep moving the goal posts.

My gut says strongly that (2) is correct. This is not to say that adaptation, etc. do not at all affect the real quality of our subjective states. I think they do. But not enough to have kept the real quality of happiness totally static over time. (Also, it might turn out that, say, adaptation is a real effect, while social comparison is a reporting effect or vice versa. But I don't want to get too complicated just now.)

How do you test this? Well, is it really that hard? There is ample reason to believe that self-reports contain real information. However, I suspect that the information they do contain is not not very usefully comparable across time and/or place. Nonetheless, we can say with a high level of certainty—due to various kinds of self-report (there is no other way)—that certain hormones and neurotransmitters, etc. correlate with feeling good, and others correlate with feeling bad. Seratonin, dopamine, oxytocin: good. Cortisol, etc.: bad. Same with certain distinctive patterns of neural activation. My friend Paul Zak takes blood samples and measures oxytocin levels to see how trusting people are. (He doesn't use self-reports, but real performance in economic games containing an assurance problem. It should also be noted gratuitously that Paul is one of Wired's 10 Sexiest Geeks for 2005.) It should in principle be possible to measure the quantity of particular substances in people's system, or the activity levels of certain parts of the brain (generally involving a number of these substances) as a proxy for the way people really feel, as opposed to the way they say they feel.

So here's the idea: Get a good sized random sample of people in a particular society (or several societies). Measure their happiness-relevant vitals again and again over time—say, twenty years—and see what you get.

My predictions:

(a) There are multiple bases for good and bad self-reports. For example, some “very happy” people may have very consistently low cortisol levels. (Buddhist happy.) Some “very happy” people have very high status-related seratonin and testosterone levels, with a moderately high amount of cortisol. (Big honcho happy.)

(b) Many of the variables that predict high self-reports, such as income, autonomy, sociality, etc., will be shown to correlate with slightly different physical bases of good feelings. Some variables will be more seratonin related. Some variables will be more oxytocin related. Etc.

(c) The composition of the physical basis of high self-reports changes as we age.

(d) Over time, we will see shifting of the distribution of different kinds of happiness (e.g., Buddhist happiness vs. big honcho happiness) within the self-report categories due to changes in cultural, social and economic institutions.

and, finally,

(e) in year twenty (assuming social stability and a continuation of the general trend in economic growth) the percentage of the population having the physical profile(s) that predicted “very happy” in year one will have increased significantly, but the self-reports will not reflect this change.

There's probably already good evidence for (a)-(c). But let's really find out.

My intutions here were heavily primed by reading Fogel's The Escape from Hunger and Premature Death, 1700-2100. Fogel advances a very physical conception of economic productivity in terms of calories consumed and calories spent. I was astonished to see the huge spike in economic productivity with the discovery of the germ theory of disease and the advent of adequate sanitation. Prior to this, almost everyone had some kind of infection almost all the time, and a big portion of the calorie budget went into fighting infection, and not productive labor. If you're not constantly sick, you have more energy and can work harder longer.

The thing that struck me is that people who were sick all the time cannot have really felt all that well. But people who were sick all the time wouldn't have a good idea of what it meant to feel not sick all the time, either. That's just the way things were. And I suspect that had folks in 1880 or whenever answered happiness surveys, they'd mostly say they were doing pretty good, like now. I bet you'd see a upward shift in the self-reports with good public health measures. But I highly doubt the shift would really correspond to the real change in what it felt like on the inside to move from really high to pretty low rates of infection. (I'd like to know the physical correlates for the lousy feelings of bacterial and viral infection. Couldn't we measure those, too?)

So, there's a research program for the taking! If you're a super-rich patron looking to make a big contribution to the science of human well-being, well, you know how to reach me!

[Cross-posted from Happiness and Public Policy.]