Do You Believe?

In my last post I mentioned that deep down I wanted to be a scientist. I’m sometimes asked why. Often I answer that I wanted to be a scientist because of Gilligan’s Island and Jonny Quest. Usually around that time people seem to remember the old quip about psychologists – that there are two kinds of people who go into psychology, the ones who want to help and the ones who need help – and decide that I belong in the latter group. But stick with me a minute because it actually makes sense. First, think about the Professor on Gilligan’s Island. He was a scientist who knew just about everything (except how to fix a boat). He was the rational, objective guy who people went to in order to solve whatever problems might arise on the island. That’s a pretty cool kind of a guy to be, right? And it wasn’t Jonny Quest who impressed me, it was his father Benton Quest¹, the government scientist who was so important that he rated some sort of secret agent guy to protect his family so he could make cool jet packs and stuff without worrying about the bad guys. Again, a cool sort of a guy to be. So, I wanted to be a scientist. I ended up in psychology because I wanted to be a ghost buster (before the movie even existed), but that’s a story for another time.

Ok, so what’s so cool about science? I think the answer to that was summed up quite nicely by Carol Tavris, a social psychologist, back in 2001 when she wrote in the APS Observer, “When psychological scientists speak to or write for general audiences, they should take the opportunity to model the key themes of scientific and critical thinking: that what we know is inseparable from how we know it; that opinions must be based on evidence; that not all opinions have equal validity; and that science gives us probabilities - only pseudoscience gives us certainties.” What I think is important in this quote is the middle bit – the bit about opinions.

When I talk about that part, I start with the last statement – that not all opinions have equal validity – first. The whole idea that some opinions are more valid – are better – than others really rubs a lot of people the wrong way. In some realms, it might be true that one opinion is just as good as another. Whether Kirk or Picard is the better captain may be one of those², along with discussion of whether the blue or the green drapes go better in the living room. But, when you’re trying to discover what’s true about the world, some opinions are better than others.

The better opinions are the ones that rest on evidence. If, for instance, Waldo thinks that short-term memory has unlimited capacity and George thinks that short-term memory has a limited capacity, George has the better opinion: there’s tons of evidence that short-term memory capacity is limited to just a few items (beginning with Miller’s 1956 paper The Magical Number Seven, Plus or Minus Two: Some Limits on our Capacity for Processing Information).

Like opinions, not all evidence is created equal. Every first-year psychology student is taught the mantra, “Correlation does not imply causation.” For a great example why, see http://www.dilbert.com/2011-11-28/. The pointy-haired boss has evidence, but it’s not as good as he thinks. He should have run an experiment to test his hypothesis that Dilbert is dissing him; after all, as far back as 1600 William Gilbert wrote, “In the discovery of secret things and in the investigation of hidden causes, stronger reasons are obtained from sure experiments and demonstrated arguments than from probable conjectures and the opinions of philosophical speculators.” I could go on about the strengths and weaknesses of various research methods, but this isn’t the time or place.

Ok, some will say at this point, science is good, but it’s not the only way of knowing, right? What about the other ways? Often such people will point to Charles Pierce’s 1877 paper and say, he talked about all the different ways of knowing. What about those other ways? Sorry, but that’s not what Pierce was doing. Pierce was evaluating reasons people might have to hold beliefs (opinions). He talked about four reasons: tenacity, authority, the a priori method, and science. He concluded that the only one of those that results in holding true beliefs was science. (Don’t believe me? You can read the paper for yourself here: http://www.peirce.org/writings/p107.html).

So, what do you believe? Does life begin at conception, at birth, or some other time? Are humans involved in global warming or not? Is the death penalty effective at deterring crime? Can humans multitask well enough to drive and text at the same time?

Now tell me: why do you believe what you believe?

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¹ Put a pair of glasses and a sweater vest on this guy and who does he remind you of?

² Picard, obviously.