Fish Stories

In my book, I describe fish that make choices like we do, learn to follow gestures, enjoy roller coaster-like sensations, and handle delays to rewards (and more).

Naturally, aquarium fish can learn to do things like swim through a hoop, and you can view cute videos on both of the animal training/enrichment websites in my "Links" page:  Karen Pryor's www.clickertraining.com/library (also check out the blogs) and Mary Hunter's www.stalecheerios.com/blog. On youtube, you might want to take a look at "Phish’s Target Training" and "Limbo Perch clicker training."  Yup, perch can do the limbo.

What about fish in the wild?  One way that wild fish got to show off provided a great example of signal learning in a lab many years ago.  What actually happens in their natural habitat may involve much of the whole nature-nurture system. 

For generations, people knew that salmon fry hatched in freshwater, swam to the sea, grew large, and then returned to freshwater streams to spawn.  But which streams?  Early experiments in which the young salmon were distinctively marked or tagged showed that they returned to the same streams where they started.  Yet there they were in adulthood, hundreds or even thousands of miles from their homes.  How could they find their way back?  Many suggestions were offered, but I don’t believe anyone guessed part of the answer:  When they get close, they smell their way to their birth stream.

Step back in time.  One 1950s research project rewarded salmon for learning to tell the difference between 14 kinds of aquatic plants by smell.  They did just fine.  Given this clue, follow-ups confirmed that salmon could smell the difference between water from different streams (and had preferences).  Why do they wait for years to return?  As always, "it's a system," and there clearly are unlearned, "instinctive"-type components in this case--the sort of interaction described in my book.

Now that so many salmon runs have been driven to extinction or near-extinction, it’s especially important to try to understand how salmon homing works.  In a recent research article in Transactions of the American Fisheries Society, Andrew Dittman and his colleagues noted that chinook salmon reared in hatcheries sometimes homed as expected when the time came, but all too frequently returned to spawn miles away from where they had carefully been released--and that's a problem for restoration efforts.  Does this modifiability reflect any learning from consequences?  We don’t know for sure, but as Dittman mentioned, the full story probably includes many elements of the nature-nurture system.  That's just what we’ve come to expect.  

Categories are Cool

So I’ve added an extra set of them!  A sidebar on the right already lets you see which of my posts have been the most popular.  (The one on "Extra Signals" wins by a large margin.)  But some of my readers have said they’d like a way just to pick out the applications--or the animal entries--or the stories relating to everyday life.  I’ve now added an additional categorization system to make that easier.  In Blogger, it’s called "Labels."  The labels (like "everyday") now appear after each blog entry, and clicking on any label brings up all my entries in that category.  I’ve also added a right sidebar that lists all these labels in one convenient location, and again, clicking on them there bring up all those entries. 

Let me know if you like the system the way I’ve set it up, or if you think I need to add some new labels.  And thanks for checking out my blog!

Keeping Safety on Track

The Thanksgiving holiday is the busiest travel weekend of the year in the United States.  That got me thinking about transport safety, and what a positive approach can accomplish.

In my chapter on work, I discuss a famously successful study introducing a positive approach to safety at two pit mines--very dangerous workplaces.  This sort of "behavior-based safety" approach has taken off. (Note, however, that a number of different approaches have been described under that name, and not all are systems-, positives-, and science-based.)  My colleague Matt Normand runs a website with useful links to stories about the science of consequences, www.behavioral-science.org.  He discovered a recent article in Progressive Railroading magazine covering the introduction of this comprehensive safety approach at a railroad.  The full story is available by scrolling to the entry for November 15 on his website and clicking on the title, "Improving Railroad Safety by Instituting a Behavior-based Safety Culture."  I particularly liked the way in which workers at all levels were helping to shape the program.  Gotta keep 'em rolling--safely.

For my US readers:  Have a safe and happy Thanksgiving weekend!

Looking the Other Way: Consequences and the "Ostrich Effect"

Sam Kean wrote recently about his unanticipated response when he had his genome sequenced for a book he was writing.  His grandfather had died of Parkinson’s disease, and when push came to shove, Sam realized that he didn’t want to know if he had inherited a genetic predisposition for it.  "I blacked that information out."  (See this link for the article in The Scientist magazine.)

Sam’s not alone in not wanting to risk bad news even when knowing it might be helpful in preparing for it.  As Sam noted, Nobel laureate James Watson had a similar reaction when he had his genome read.  Less serious, everyday examples aren’t hard to come by either.  I know I sometimes turn off the radio when bad news is broadcast.  The consequences of staying tuned in are just too discouraging.  In my book, I refer to this as the "ostrich effect." 

It may not be all that surprising that animals respond similarly to the prospect of bad news.  Pigeons, for example, learned to peck for a signal indicating the schedule of reinforcement that they could currently work on.  This schedule switched back and forth unpredictably, so the best way to optimize their efforts was to peck periodically for the signal during lean times when few or no rewards could be earned.  Eventually, a more encouraging signal would tell them good times had returned.  Unfortunately, the "bad news" signal stopped most of the birds in their tracks (and thus acted as a punisher)--an effect that's been demonstrated in a number of species now, even fish.  And as we’ve seen, for all our sophisticated intellects and fancy delay-bridging rules and rationalizations, people frequently behave the same way, both in the lab and in real life.  That's the case even when the bad news could be really important.  One of the examples in my book is the large Centers for Disease Control estimate of the number of HIV-positive people in the United States who have avoided taking the simple, inexpensive test to check their status.  Some of them may unknowingly be spreading the disease.

Sam Kean eventually worked up the courage to confront his fears about his possible genetic predisposition to Parkinson’s, and get the facts.  Just as ostriches don’t really bury their heads in the sand, we can learn to face potentially bad news.  What we know about the science of consequences can help us do so.  It still isn’t easy, though.  Anyone want to share examples of how they coped with this all-too-common challenge?

Expanded Website

Just a short post:  Now that my book is so close to publication, I've added "Events" and "Reviews & Media" webpages.  Let me know what you think!