Data Science & Psychology Data Science applied to Values, Morals, Politics, & things that matter.

Psychology is generally Continuous, not Categorical

We live in a world where we often have to make categorical decisions.  We date someone or we don't.  We marry them or we don't.  We hire someone or we don't.  We pick either the Democrat or the Republican.  There is no middle ground.

Unfortunately, the world isn't necessarily organized in that fashion.  Few would believe there are such categorical distinctions.  Prospective dates have some degree of positive and negative qualities, rather than attributes being merely present or absent.  Are people either qualified or not for a job?  Most people instead belong along a continuum of professional ability, with some being very qualified (way above being merely adequately qualified) and some people being just below and just above the border of qualification.  Politicians aren't uniformly liberal or conservative and we routinely see partisans on both sides upset at those who aren't extreme enough and who toe the partisan line.

This may seem obvious, but the reason I bring it up now is that while most everyone would agree with this fact, when thought about more carefully, still many people continue to argue as if things are categorical.  There are two recent examples on the yourmorals blog.

First, the comment section of this post has become a debate (for many) over whether psychology is objective (science) or subjective (art).  Allow me to quote Gene, from this thread:

there is SOME objective knowledge that comes from psych research (anything that can be experimentally shown, is predictive, even if only statistically, it has value).

If you want to get really nitty gritty, even physics is not completely “objective”…it’s merely instrumental to understanding objectivity (see here: http://en.wikipedia.org/wiki/Instrumentalism)

Most things are not completely objective or completely subjective, especially where human affect, behavior, and cognition is concerned.  Yes, psychology is less objective than physics...but it's more objective than sculpture.  If I think that Paul McCartney sings better than I do, is that an objective or a subjective fact?  It's objective in so far as a survey of people would detect a very large statistically significant difference between perceptions of our singing.  But it's subjective in so far as it may not be true for a particular person (e.g. my wife and my mom).

What complicates things further is that many people who read psychology don't really care about what happens to most people, but rather how the research applies to them.  Consider this very useful overview of how changing our consumption patterns can make people happier.  One of the recommendations is something that I tell people often, that experiences lead to more happiness than material things, an opinion shared by 57% of a national sample (and shown to be true for most in experimental research).  Yet, 34% of those people disagree (and some don't benefit in experiments).  So is the statement that "buying experiences leads to more happiness than buying things" an objective or a subjective fact?  It's true for a majority of people, but not for a significant minority.  It's likely true for many groups, but certainly not all groups.  Yet many people still think we can definitively decide if psychology is objective or subjective, even though humans, unlike inanimate objects, don't react predictably to situations, except perhaps in aggregate (e.g. we have free will or at least the illusion of it).  I can find truths that apply to all rocks or all electrons, but not for all humans.  But I can find truths that apply to many humans or most humans, and that might give someone insight into themselves, which is a valuable thing.

A second instance of categorical thinking on the yourmorals blog of late is Pigliucci's critique of Haidt's recent SPSP speech.  Haidt pointed out that there is underrepresentation of conservatives in social psychology compared to the population and cites both self-selection and discrimination as issues to varying degrees.  Many people (understandably) focus on the sexier charge of discrimination, and Pigliucci answered that he "suspect(s)  the obvious reason for the “imbalance” of political views in academia is that the low pay, long time before one gets to tenure (if ever), frequent rejection rates from journals and funding agencies, and the necessity to constantly engage one’s critical thinking skills naturally select against conservatives."  But what if causality was continuous and not categorical.  Pigliucci may be entirely right about his obvious reason, yet there still could be some amount of discrimination.  Indeed, if there is one student somewhere whose ideas are supressed (and there was at least one in Haidt's talk), then there is at least some degree of both self-selection and discrimination, meaning that a debate over what statistically causes underrepresentation misses the point.  Bear in mind that these are not just data points, but actual human beings.  One human being discriminated against is one human being we could serve better, even if the vast majority of under-representation is due to self-selection.

I'm obviously biased in the above debate, but these thoughts are not a response to that debate, but rather a response to almost every debate and decision I see in psychology.  Some other things that are continuous, and not categorical:

Journal Publication - Editors have to make categorical decisions to accept or reject papers, yet many papers that are accepted never get cited, while other papers are published through sheer persistence down the chain of  journal prominence.

Statistical Significance - A 94.9% chance of being right is not that different than a 95.1% chance of being right, yet it is treated as a categorical distinction called "significance" because we need to be able to say whether something is true or not, when in reality, all we have is some evidence toward the truth, that varies to some degree.  Even the best paper does not definitively prove anything and even the worst paper is some evidence toward something.

Authorship - Many people work on papers (often undergraduate research assistants) and are not authors, while others do fairly little and receive authorship.  Sometimes the first author does 90% of the work and sometimes they do 51%.  Yet they still receive the categorical distinction of first author.

Psychological conditions - Few psychological clinical conditions are categorical.  In reality, people have some degree of anxiety, rather than having or not having an anxiety disorder.  Yet, for insurance reasons, people have to be diagnosed categorically as having a particular condition.

Psychological constructs - Is shame the same as guilt or different?  Is shame the same as sadness?  Is shame the same as happiness?  The truth is that shame is somewhat like some of these constructs and less like others of these constructs.  Categorical distinctions between such constructs are useful for publications, but don't really reflect the continuous nature of the real world.

I am sure that if I thought more, I could come up with many more examples of things that are continuous, but treated as categorical. In academia, perhaps we can eventually change our systems, leveraging technology, to acknowledge the continuous nature of things.  My real-world hope, as someone who believes that a world with less conflict is better than a world with more conflict, is that perhaps seeing things as continuous, rather than categorical, means that people will be less likely to make harsh judgments of others based on the idea that their beliefs are the categorical caricatures that we make them out to be.

- Ravi Iyer