What have you changed your mind about?

A couple of months ago I wrote about Edge Foundation's What is your formula? question. Well, the results of the Edge annual question for 2008 are now online. The question posed to Edge's contributing scientists and thinkers this time around was, What have you changed your mind about? Why? (You'll need to scroll down past a bunch of blurbs on that page before you come to the list of responses.)

It's a challenging question to answer, and I was expecting some intriguing responses. There are some interesting answers, to be sure, but not as many as I initially expected. In retrospect, I guess that's not too surprising. (Ha! Look, I changed my mind about that!) Since a change of thinking is required, it kind of implies that the holder's original point of view was wrong. So, if someone has an important idea, but it is their original point of view on a subject, then it just isn't going to show up in this year's mix. In fact, in browsing through the responses I frequently found myself thinking, "Of course you changed your mind--your original ideas were clearly wrong!" And there were also a couple of entries were I'm pretty sure the authors changed their minds in the wrong direction.

When I try to answer this question for myself, I have a hard time coming up with a clear-cut example. Of course, there are lots of little mundane day-to-day opinions that change, like what kind of toppings I like on my hot dogs. But for the "big ideas", it's more a matter of gradual refinement over time as I learn more about a subject, than a complete change in direction. (I am of course limiting myself to my opinions as a mature adult. If my opinions during my teen years were included, I'm sure my parents could produce many examples where I've since done a complete about-face, but thankfully I have pretty much total amnesia about that time of my life.)

Here are just a few selections that struck me as I read through them...

Susan Blackmore talks about how she stopped believing in paranormal phenomenon. I've never been a real believer in this kind of stuff, but I did spend a lot of time researching it in college because it's the kind of thing that would be so cool if only it were true. I quickly realized, however, that nearly all the research published in parapsychology journals was just plain crap. It made me wonder how any self-respecting scientist could continue to work in the field.

I had to re-read Daniel Hillis's entry more than once to convince myself that I understood him correctly. He talks about how, as a child, he was told that hot water froze faster than cold water and he refused to believe it because it defied common sense. He challenges the reader to try the experiment for themselves in order to convince themselves otherwise. I'm pretty sure that he's just trying to taunt us into adopting an experimentalist mindset, but I'll be damned if I'm not going to have to try this for myself now.

Many respondents talked about changes in religious belief. Conflicts between fundamentalist religious beliefs and science have been in the news a lot lately (for example, in the context of the primary election debates), but moderate religious beliefs are generally portrayed as compatible with modern science. Clay Shirky has come to disagree with this perspective and argues that even moderate beliefs are not reconcilable with science, and we are entering a long period of societal restructuring on this issue.

Finally, there were a number of mathematically oriented entries. These tended to deal with philosophical shifts, such as Keith Devlin's move away from platonism and toward socially or evolutionarily constructed mathematics. But Bart Kosko had a very specific change of mind: he argues that the median should be the preferred measure of central tendency, instead of the mean.