Replicability in personality psychology, and the symbiosis between cumulative science and reproducible science

There is apparently an idea going around that personality psychologists are sitting on the sidelines having a moment of schadenfreude during the whole social psychology Replicability Crisis thing.

Not true.

The Association for Research in Personality conference just wrapped up in St. Louis. It was a great conference, with lots of terrific research. (Highlight: watching three of my students give kickass presentations.) And the ongoing scientific discussion about openness and reproducibility had a definite, noticeable effect on the program.

The most obvious influence was the (packed) opening session on reproducibility. First, Rich Lucas talked about the effects of JRP’s recent policy of requiring authors to explicitly talk about power and sample size decisions. The policy has had a noticeable impact on sample sizes of published papers, without major side effects like tilting toward college samples or cheap self-report measures.

Second, Simine Vazire talked about the particular challenges of addressing openness and replicability in personality psychology. A lot of the discussion in psychology has been driven by experimental psychologists, and Simine talked about what the general issues that cut across all of science look like when applied in particular to personality psychology. One cool recommendation she had (not just for personality psychologists) was to imagine that you had to include a “Most Damning Result” section in your paper, where you had to report the one result that looked worst for your hypothesis. How would that change your thinking?*

Third, David Condon talked about particular issues for early-career researchers, though really it was for anyone who wants to keep learning – he had a charming story of how he was inspired by seeing one of his big-name intellectual heroes give a major award address at a conference, then show up the next morning for an “Introduction to R” workshop. He talked a lot about tools and technology that we can use to help us do more open, reproducible science.

And finally, Dan Mroczek talked about research he has been doing with a large consortium to try to do reproducible research with existing longitudinal datasets. They have been using an integrated data analysis framework as a way of combining longitudinal datasets to test novel questions, and to look at issues like generalizability and reproducibility across existing data. Dan’s talk was a particularly good example of why we need broad participation in the replicability conversation. We all care about the same broad issues, but the particular solutions that experimental social psychologists identify aren’t going to work for everybody.

In addition to its obvious presence in the plenary session, reproducibility and openness seemed to suffuse the conference. As Rick Robins pointed out to me, there seemed to be a lot more people presenting null findings in a more open, frank way. And talk of which findings were replicated and which weren’t, people tempering conclusions from initial data, etc. was common and totally well received like it was a normal part of science. Imagine that.

One things that stuck out at me in particular was the relationship between reproducible science and cumulative science. Usually I think of the first helping the second; you need robust, reproducible findings as a foundation before you can either dig deeper into process or expand out in various ways. But in many ways, the conference reminded me that the reverse is true as well: cumulative science helps reproducibility.

When people are working on the same or related problems, using the same or related constructs and measures, etc. then it becomes much easier to do robust, reproducible science. In many ways structural models like the Big Five have helped personality psychology with that. For example, the integrated data analysis that Dan talked about requires you to have measures of the same constructs in every dataset. The Big Five provide a common coordinate system to map different trait measures onto, even if they weren’t originally conceptualized that way. Psychology needs more models like that in other domains – common coordinate systems of constructs and measures that help make sense of how different research programs fit together.

And Simine talked about (and has blogged about) the idea that we should collect fewer but better datasets, with more power and better but more labor-intensive methods. If we are open with our data, we can do something really well, and then combine or look across datasets better to take advantage of what other people do really well – but only if we are all working on the same things so that there is enough useful commonality across all those open datasets.

That means we need to move away from a career model of science where every researcher is supposed to have an effect, construct, or theory that is their own little domain that they’re king or queen of. Personality psychology used to be that way, but the Big Five has been a major counter to that, at least in the domain of traits. That kind of convergence isn’t problem-free — the model needs to evolve (Big Six, anyone?), which means that people need the freedom to work outside of it; and it can’t try to subsume things that are outside of its zone of relevance. Some people certainly won’t love it – there’s a certain satisfaction to being the World’s Leading Expert on X, even if X is some construct or process that only you and maybe your former students are studying. But that’s where other fields have gone, even going as far as expanding beyond the single-investigator lab model: Big Science is the norm in many parts of physics, genomics, and other fields. With the kinds of problems we are trying to solve in psychology – not just our reproducibility problems, but our substantive scientific ones — that may increasingly be a model for us as well.



* Actually, I don’t think she was only imagining. Simine is the incoming editor at SPPS.** Give it a try, I bet she’ll desk-accept the first paper that does it, just on principle.

** And the main reason I now have footnotes in most of my blog posts.