Skinner's Shaping

Skinner's Shaping

A question Skinner had to deal with was how we get to more complex sorts of behaviors. He responded
with the idea of shaping, or “the method of successive approximations.” Basically, it involves first
reinforcing a behavior only vaguely similar to the one desired. Once that is established, you look out for
variations that come a little closer to what you want, and so on, until you have the animal performing a
behavior that would never show up in ordinary life. Skinner and his students have been quite successful
in teaching simple animals to do some quite extraordinary things. My favorite is teaching pigeons to
bowl!

I used shaping on one of my daughters once. She was about three or four years old, and was afraid to
go down a particular slide. So I picked her up, put her at the end of the slide, asked if she was okay and
if she could jump down. She did, of course, and I showered her with praise. I then picked her up and
put her a foot or so up the slide, asked her if she was okay, and asked her to slide down and jump off.
So far so good. I repeated this again and again, each time moving her a little up the slide, and backing
off if she got nervous. Eventually, I could put her at the top of the slide and she could slide all the way
down and jump off. Unfortunately, she still couldn’t climb up the ladder, so I was a very busy father for
a while.

This is the same method that is used in the therapy called systematic desensitization, invented by
another behaviorist named Joseph Wolpe. A person with a phobia -- say of spiders -- would be asked to
come up with ten scenarios involving spiders and panic of one degree or another. The first scenario
would be a very mild one -- say seeing a small spider at a great distance outdoors. The second would be
a little more scary, and so on, until the tenth scenario would involve something totally terrifying -- say a
tarantula climbing on your face while you’re driving your car at a hundred miles an hour! The therapist
will then teach you how to relax your muscles -- which is incompatible with anxiety. After you practice
that for a few days, you come back and you and the therapist go through your scenarios, one step at a
time, making sure you stay relaxed, backing off if necessary, until you can finally imagine the tarantula
while remaining perfectly tension-free.

This is a technique quite near and dear to me because I did in fact have a spider phobia, and did in fact
get rid of it with systematic desensitization. It worked so well that, after one session (beyond the
original scenario-writing and muscle-training session) I could go out an pick up a daddy-long-legs. Cool.
Beyond these fairly simple examples, shaping also accounts for the most complex of behaviors. You
don’t, for example, become a brain surgeon by stumbling into an operating theater, cutting open
someone's head, successfully removing a tumor, and being rewarded with prestige and a hefty
paycheck, along the lines of the rat in the Skinner box. Instead, you are gently shaped by your
environment to enjoy certain things, do well in school, take a certain bio class, see a doctor movie
perhaps, have a good hospital visit, enter med school, be encouraged to drift towards brain surgery as a
speciality, and so on. This could be something your parents were carefully doing to you, as if you were a
rat in a cage. But much more likely, this is something that was more or less unintentional.

Open Ended

Use your own words to describe what shaping is.

Open Ended

Use your own words to describe how systematic desensitization works.