Measure for Measure: Rival Ways of Knowing

In recent months, I seem to have been embroiled in a number of arguments that basically turn on issues about knowing--- how we know, and how we know that we know. A recent one of these is at http://marginalperspectives.com/2011/01/silence-no-harm-seriously.html.
Contributors to that blog took me to task for having said that there had been no reported harm as a result of unusual childhood experiences like those of the much-discussed “practice babies” of the ‘50s and that this was a meaningful fact. They attributed to me the belief that if something cannot be measured, it must not exist. (This is, by the way, a point often discussed by proponents of complementary-and-alternative therapies; see M. Kane [2002], Research made easy in complementary and alternative medicine. London: Elsevier).

Actually, my position, like that of most scientifically-trained psychologists, is that if something cannot be measured, it may or may not exist. We may simply not have developed the right measurement techniques yet. Similarly, if something is said to have been measured, it also may , or may not exist; mistakes may have occurred in the measurement process.

So why would we measure, if neither measurement or the absence of measurement gives us a clear answer? The reason is simple: measurement by agreed-on methods is the only way we can share experience with other people and ask them to confirm our impressions. The whole point of scientific method is that it allows information to be made public, and for each person’s report to be checked by many other people who use the same measurement techniques as the initial observer.

When information is checked against other reports, there are many cases in which later observers fail to confirm the first observations. A famous example is the “Piagetian reach”. This was a phenomenon described by the famous developmentalist Jean Piaget. He reported that when a baby first started reaching for objects, she would look at the object, then at her hand, then at the object, and so on, as she brought her hand closer to the goal. Makes sense, of course-- but it turns out that no one else has ever seen such a thing. It took a while for anyone to realize that the Piagetian reach doesn’t seem to exist, because at first people were embarrassed that they were not as good observers as M. Piaget. Today, improved measurement and recording devices have shown a very different pattern in early reaching than the one Piaget thought he had seen.

Measurement lets us check and re-check what we think we know, and allows scientific evidence to be self-correcting-- although that process of self-correction is admittedly slow and clumsy at times, it can work well.

What’s the rival way of knowing? It’s an approach shared by Oprah, Ralph Waldo Emerson, and many of today’s bloggers. We might call it “personal truth”. Emerson spoke of it as Reason-- defined as knowledge shared with God or the “World-Soul” and present in all souls-- as opposed to Understanding based on systematic observation. (“Personal truths” may be claimed to be based on unsystematic observation, of course.) In this approach, what one person experiences as being true IS true, because it comes from Reason, and there is no need to check and re-check against the observations of others, or to use measurements that can be shared by others. No observation or argument from another person can shake commitment to a “personal truth”, and here we have yet another reason why Jenny McCarthy will not be convinced by the Wakefield scandal.

I support the approach to knowledge that uses measurement and public scrutiny to support or fail to support an idea. Having given some thought to the complexities of measurement and public communication, I find these issues too humbling and challenging for me to ignore. I do not put my “personal truths” (and of course I have some) forward and insist that others should agree to them, but neither am I willing to accept others’ “personal truths” without question.

Neither of these ways of knowing is any guarantee of being right. The emphasis on repeated measurement has a great advantage in the face of challenges, however: it contains ways to figure out what is wrong and to strive for correction. “Personal truth”, on the other hand, simply becomes more definite when challenged. If a matter affected me alone,I might venture to follow "personal truth", but when more people may be affected, I think it's only fair to invite others to check my claims.