Why is Psychology not a exact Science?

-- Tim R Pohle (sacramento51@hotmail.com), October 11, 2001

Answers

This question has come up recently. You might find interesting the answers at http://hv.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=004us4

-- Christopher Green (christo@yorku.ca), October 11, 2001.

psychology cannot now or may never be able to be called an exact science. Historically, all sciences have either been proved or disproved with hard facts (Aristotle/ptolemy-heliocentric theories of the solar system, Kepler/galileo etc-geocentric solar system, proved through the dutch invetion of the telescope). The problem when dealing with the mind is that not enough is known about it and it's delicate intracasies to acurately discuss the exact science of it. Many have tried and came up with theories diagnoses of problems and cures for abnormalities, dealing with certain aspects of the mind but little is known of the origins of thought, individualism, and how it is all linked. To say one knows all there is to know about the mind is like saying that there is tangable evidence to the existense of a soul or even God for that matter.

-- (ashby@southkent.net), October 15, 2001.

I'd like to propose a differing perspectice from the answer given by my friend. How exact are the "exact" sciences? and what does that exactness rely on? To show what I mean take a look at the science of crystalography. The theory of crystals defines 230 space groups, or shapes, that are possible shapes for a crystal. *But* numerous crystals occur in nature that do not conform to the theory. That emperical fact is taken to be a flaw in the crystal (nature) and not a flaw in the theory. The hard facts about crystals does not compel physics to abandon the theory. (This is not a criticism of physics. Rather, it is to suggest that physics as portrayed by Logical Empericism is mistaken.)

We may draw the conclusion that psychology is inexact becase psychology does not precict behaviour very well. But if we apply that criticism to psychology why not apply it to crystalography, a theory that doesn't predict the exact shape of crystals very well. We don't do the latter so why the former?

Just as physics retains theories that don't conform exactly to our experience of nature, psychology retains theories that don't conform to every irregularity of human nature.

Moreover, while a crystalograper relys on his theory to make a judgement about what is and isn't a flawed crystal, psychology relies on their theories to distinguish a normal psyche from an abnormal one.

But why? Why is physics and psychology in the same boat? I think humans prefer theories that point to the order in nature, not the disorder/chaos in nature. Seeking order is one of the guiding values that permeates both natural and social sciences.

So now the original question may become not why is psychology inexact? but, is the order in human nature different from the order in the things physics studies? If so, what is that human order, what principles does that order operate by, and what methods could we devise to demonstrate it?

Nevertheless, your question may be pointing to why are there so may schools of psychology? There are basically two types of psychology, deterministic psychology and freedom psychology. Those two types trace back to the beginning of the modern age. In the beginning nature was defined as what could be spacially measured. The mind coud not be measured that way so it was deemed to be in some sense 'outside nature'. Because the body could be measured (in inches) and the mind couldn't the so called "mind/body" problem was born. Moreover, nature, hence the body, was deemed to be mechanical and deterministic. What to do with freedom? That must be 'outside nature' in ths same place as the mind/psyche/soul/self.

That nature/outside nature, body/mind, determinism/freedom duality has shaped modern psychology. Freedom, or humanistic psychology, then, disagrees with deterministic psychology because freedom and determinism are logically incompatable.

As long as psychology accepts its modern philosophical roots (Descartes, Locke) and assumptions there will always be disagreement between the two most general schools of psychology.

The path out of this is, I think, to reexamine the reasoning that got the mind into a realm outside nature. If we abandon the idea that nature is what can be measured in inches, then we don't need to place the mind in a realm 'outside nature'. Just because we can not measure an experience, the experience of joy, for instance, doesn't prove that joy is 'outside nature'.

Secondly, if we abandon the idea that everything in nature operates according to strictly mechanical principles then we don't have to draw the conclusion that freedom is 'outside nature' too. The idea that nature can not produce a sentient being capable of original acts is, I think, a false belief. There is no compelling reason to believe that sentient beings are as mechanical as non-sentient beings.

Now, having put those Cartesian assumptions in abayance, we can talk of humans as sentient creatures capable of making choices (without presupposing two logically incompatible realms.) With the dissolution of the two Cartesian realms, the boundary between freedom psychology and deterministic psychology vanishes.

-- John Hedlin (jhedlin@canada.com), October 21, 2001.