Monday, July 13, 2015

Why Psychologists Study Behavior, Not the Mind

Image source: Flickr
For psychology, behavior is always the subject matter, despite what some might claim to the contrary. At the end of the day, all that psychologists can measure is behavior. Even the psychologist who claims to study the mind is, in practice, studying behavior. There is behavior and there is the nervous system, but everything else is an inference. To infer something between the nervous system and behavior is dualistic, and so much the worse for the progress of psychology as a science.

Consider the following example. We want to know if understanding a question written in all capital letters without any punctuation is more difficult than understanding a question written normally. We hypothesize that it will take longer for subjects to answer if the question is more difficult to understand. We present the following question to half of our subjects:

"JIM HAS FIVE DOLLARS JOHN HAS TWO DOLLARS HOW MANY MORE DOLLARS THAN JOHN DOES JIM HAVE"

We present the following question to the other half of our subjects :

"Jim has five dollars. John has two dollars. How many more dollars than John does Jim have?"

Suppose that subjects in the first group take, on average, 5 seconds to answer. And suppose that subjects in the second group take, on average, 1 second to answer. We conclude that the first question--the one in all capitals with no punctuation--was harder to understand. Further, we conclude that it took the subjects seeing the first question longer to "process" the question, with the "processing" presumably being some cognitive processing taking place in the brain.

We might, and psychologists often do, assume that we are measuring cognitive processing of some sort with our experiment. But are we?

What we really are measuring is the relationship between the way a question is printed and the length of time (termed "latency") it takes subjects to answer the question. Providing an answer to the question is behavior and that is what we see and measure. We haven't measured a cognitive process, then, we've measured behavior. We infer the cognitive process from the behavior we observed.

But someone else might infer a very different thing from the very same situation. Maybe another researcher would infer that seeing all capitals and no punctuation makes the subject first say to themselves, "I wonder why the question is written in all capitals with no punctuation." Saying this before answering the question is what accounts for the increased time it takes them to answer the question. Still another research might infer something very different.

There can be no real disagreement about the response latency observed. It is objective, well defined, and easily recorded. No inferences necessary. That is the great benefit of approaching psychology as a science of behavior: it is conservative and assumes no more than what can be established through direct empirical investigation.

Put simply, behavior is anything an organism does. More specifically, behavior is the interaction of the muscles and glands of a live organism with the environment. For scientific purposes, we need to add a caveat. Behavior is anything an organism does that is observable and measurable. If we can't in some way see it, we can't measure it. If we can't measure it, we can't study it.

Talking is behavior. Running is behavior. Pedaling a bike is behavior. Writing an answer on an exam is behavior. Taking notes in class is behavior.

Things like understanding, knowing, loving, and even learning, are not behavior mostly because they are too vague--they are just labels for various kinds of actual behavior. Loving, for example, doesn't specify anything in particular and, not surprisingly, there is a lot of disagreement about what love is and how you would go about studying it. We can simplify things and get a foothold on studying something like "love" if we just identify some actual behavior that we believe to be relevant. We might decide to study how often a husband compliments his wife (and vice versa). We might study how often a wife says nice things about her husband to other people (and vice versa). We might study how close a husband and wife sit to one another at dinner or at a party.

Really, we'd have to identify a whole host of behaviors like those above and study them in concert--no easy feat, to be sure. Absent a clear definition of what we're studying and a way to record what we're studying, we'll be spinning our wheels.

Science is mostly a slow incremental endeavor. You can't start with all the answers to the most important questions. First you have to find out what questions to ask. For psychology, you have to figure out what behavior is relevant and how to measure it.

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