By Matt Richter

Let's use an adapted scenario from Tim Harford's wonderful book, THE DATA DETECTIVE.

Your arm hurts. You go to the doctor. The doctor prescribes physical therapy. You go. After two weeks you feel better.

The doctor was correct, right?

You say yes.

The statistician says the doctor may have been right, but you may have gotten better on your own without intervention. Or, maybe something else accelerated your improvement. Or, maybe the therapy made things worse, and you would have gotten better a week earlier without it.

As Tim says, you probably don't care- you're better! But doctors do care. Why? Because using the wrong solution (albeit a correlated one) won't work for the majority over time. Doctors encounter lots of patients with arm problems and if PT has a CAUSAL relationship to improving the situation, they can reliably prescribe it. If it doesn't, or makes the problem worse, then other treatments must be used.

This is the difference between personal experience (you got better and that's all that matters) and statistically sound approaches to solving the problem for the many.

The reverse can also happen. Just because there is a statistically sound treatment likely to work, doesn't mean FOR YOU, it necessarily will. Aberrations happen! That is why statistics work with probabilities.

For L&D, are we the patient in this analogy? Or, are we the doctors, prescribing a solution? In our professional context, we need to think like a doctor. Which means we need to separate personal experience ("it worked," or "I think it worked,") from the statistical view ("it worked because of 'x'").

In other words, we need to differentiate correlations (PT & getting better happened close together) and the cause (physical therapy MADE the patient get better).

Does the use of MBTI or DiSC increase the level of self-awareness among leaders? Does that self-awareness make them better leaders?

What is important, however, is that participants are actually more ACCURATELY self-aware- step one. And, then that ACCURATE self-awareness increased leadership acumen according to a measurable and defined standard.

Participants often say these tools work. Why? Their personal experience. These tools seemingly provide insightful information. Being self-aware is popularly seen as significant to leadership. Therefore, using MBTI or DiSC absolutely increases leadership skills.

But these links are more likely due to personally experienced correlations. What do the statistics say? Most studies have debunked both these tools outright. Check out Annie Murphy Paul's, THE CULT OF PERSONALITY.

In L&D, we are like the doctor. We want to use solutions that help get us to our goals. But we need to see through individual experience (the trees) to the forest (the big picture). We want solutions that CAUSE improvement. Relying on research and statistics enables us to make better decisions on what works.