How to Avoid Being Misled by Statistics

How Not To Be Wrong, Good Reads.
Jordan Ellenberg (author), Twitter.

You all know, I’m sure, that 95% of statistics are made up on the spot. But can we trust those that are published in scientific journals and circulated elsewhere? Should we change our behavior when a particular study seems to recommend it?

Probably not, argues Jordan Ellenberg. How Not to be Wrong is a book about the art of mathematics, which he also talks about as the science of ‘not being wrong’. There are three points I take from the book which I think everyone reading this should take to heart:

1. Don’t think that a line on a chart has predictive value. Avoid linear thinking.

Linear thinking is people’s tendency to assume that a line drawn on a graph (loosely connecting some data) has predictive value for the future.

It’s a mistake which leads to headlines like All Americans will be obese by 2048”, to novice investors alternating between thinking they will be rich/broke, and to an inability to understand complexity. Our world does not work in lines, even if it looks like it does on a short time-scale.

Even a circle looks like a line if you zoom in far enough (search for a Chiliagon, a 1000-sided polygon, if you don’t believe me). Not to mention most relationships between two variables change over time. A line on a chart tells you nothing about the future.

2. Ignore anything you read that is backed by a single scientific study.

Studies are generally considered significant in these fields if they have a P-value of under 0.05.

Essentially what it means is that the chance of the relationship being shown in the study being random (‘null’) is under 5%. Except, as Ellenberg explores, a variety of problems including considering multiple variables, massaging data to meet “significance”, non-publication of insignificant results, and misrepresentation of studies in the media and by marketers make it near-impossible for an amateur to work out what should be believed.

So wait for the third or fourth study before you take any “science-backed” action.

3. Take anything claiming to represent public opinion with more than a pinch of salt.

The problem here is not that each individual voter is irrational. It’s that when you aggregate people’s positions, it’s nonsensical. It’s the aggregation that’s the problem – I’ll talk about this again next week.

Want to know more?

This blog post is part of a series I am making called Reading For The Aspirational Self. Don’t think of this as book summaries – I’m not doing that. Instead, I’m drawing out specific lessons that I find particularly interesting. And which I think could act, together, to help people who share my aspirations. If you, too, want to be present, family-centric, intrinsically motivated and polymathic, I can help.

  • The most distilled version of what I’m offering is a free mailing list designed for learning, “Think On Thursday” – each e-mail will include a lesson designed around the content. Click here for some information on that.
  • The series is also on YouTube in the form of 7-12 minute videos. Here’s the channel link – the video and transcript are below.
  • I’m tweeting excerpts from the videos, as well as some of the story of this project, how we’re doing it, and where it is going, on Twitter. @DaveCBeck

If you want to know more about How Not To Be Wrong take a look at Ellenberg’s website here: https://www.jordanellenberg.com/.

Starboard reflections,

Dave.

This week’s video:

The transcript can be found here: