How do we know...?

My dad identifies himself as a fundamentalist Christian.  For him, this means that the Bible is the inerrant word of god.  When you get down to the details, it means that he believes that the earth was created about 6,000 years ago over a span of 6 days.  When I was a kid, I remember a number of times when my dad and I were watching TV when some news report would announce some new scientific discovery; perhaps a new human ancestor or new evidence about the nesting habits of a dinosaur.  Inevitably, he would turn to me and say, "Now how do they know that?"  It was a rhetorical question.  He wanted me to approach these things critically and use common sense to see that they were likely as not just making shit up in hopes that we wouldn't understand or question it.

When I grew up, I thought about those questions occasionally.  How do "they" know the things they say they know?  So I started to read some books.  I was surprised that, unlike the quick news reports I saw on CNN as a kid, scientists were eager to explain exactly how they know what they know.  For every time my dad asked me the rhetorical question of how they know what they claim, there was an actual, non-rhetorical answer!

Now, with my kids, I like to do the same thing my dad used to do with me.  When we watch a show like Nova or Nature, I ask, "How do you think they know that?" Sometimes, it's an easy question for them to answer, and sometimes it's a bit more challenging.  Sometimes, I already know the answer and sometimes I don't.  Either way, it's a practice that I've enjoyed repurposing.  So, in the spirit of looking for answers to questions about how we know what we say we know, I'd like to share a link to a page on the Smithsonian  Museum of Natural History's website: How Do We Know?

I'll add more of these types of sites as I find them.  If you know of any others, let me know in the comments!

Making Choices with Incomplete Information

Jen Hancock, the Happy Humanist, has a great post on her blog about critical thinking called "How Being Less Wrong is Actually Right".  She describes how human knowledge is more a process of becoming less wrong than acquiring a sort of Holy Grail of Truth. To illustrate her point, Jen cites Asimov's description of the evolving view of the globe - from flat to round, small to big, and perfectly spherical to bulging in the middle.

This got me thinking about what I said in my post about Darwin Day and the errors of Social Darwinism, "It's not what you know that matters, it's how you approach that knowledge."  In a perfect world, we could approach all knowledge as if it existed in isolation from the rest of existence.  We could leave it undisturbed behind a velvet rope and occasionally come view it as it expands and shifts with each new experiment.  Each bit of new information could be a new facet on the surface of a perfect jewel, exposing the clarity and color previously hidden in the dull, hard stone of our initial observations.

In reality, we can't wall our knowledge off in a safe, sterile area.  Rather, each piece of knowledge is a tool that we must use each day or month or decade regardless of whether we're ready or not - whether we're confident in its accuracy or not.  Each decision we make is based upon the knowledge we have up to that point.  So here's my question: How do we factor the shifting uncertainty of each bit of knowledge into our decision making process?  Do we have conscious or unconscious processes for this?  If so, are these processes similar for everyone?  Beyond the question of how we weigh our own confidence in the information we have, what increases or decreases that confidence for different people?

My wife gave me a book by Jonah Lehrer called How We Decide that addresses some of these questions.  I've not finished the book yet, but so far my understanding of Lehrer's argument is that the decision making process is heavily influenced by a "good" or "bad" feeling we get that stems from dopamine production or transfer in the brain - often without our being aware of it.  The idea here being that, after each action, we experience a positive or negative emotion and that our brain basically begins to bypass conscious thought in familiar situations in favor of  generalizing the experiences we've had before.  This generally works out well for us.  Big scary lion teeth give us a fright because we've seen or heard of how dangerous they are.  By reacting emotionally, rather than critically, we're more likely to react quickly and evade the lion.  On the other hand, this type of decision making can be counter productive in new situations.  For example, we may not recognize a new danger if is doesn't resemble something associated with a negative emotion or we may not recognize a new opportunity if it does elicit a negative emotion.

Given all that, it seems that the trick is to be prepared in advance to respond to different types of situations differently.  In other words, we have to determine whether the situation requires a novel, considered, critical approach or an instant fight-or-flight type approach.  Either way, I'm excited about picking Lehrer's book up again to see what else he has to say.  When I'm done, I'll review it here.