Speech Complexity

In which Rat comes to love climate change

Good time of day, humans!

There’s a weird new piece of research making rounds on the internets:

The effect of temperature on language complexity: Evidence from seven million parliamentary speeches

tl;dr: the speeches politicians make on hot days are less elaborate, therefore… somehow… «climate change could affect human cognitive performance and the quality of political discourse».

There might be something to this theory but what exactly is it? It’s pretty cool in our parts today (18 °C / 64 °F right now), so I feel inclined to make an unusually long and complex speech¹.

First of all, the magnitude of the purported effect is absolutely minuscule:

In substantive terms, heat (>27°C) decreases the Flesch-Kincaid score by −0.05 or −0.45 percent. This corresponds to approximately a half month of lower educational attainment.

Imagine saying to someone: «you sound two weeks less educated today». Most folk’s performance likely varies much more than that depending on the time of day and amount of coffee consumed.

Also, the extrapolation from speech complexity to «cognitive performance and the quality of political discourse» is not based in anything. There’s no evidence more complex speeches are somehow better, and our everyday experience rather suggests the opposite.

To the credit of the authors, they’re asking the right questions:

But how can extreme outdoor temperatures have an effect on political speeches held indoors?

(emphasis in original)

…the explanations offered are however far from convincing. They somehow have missed the most trivial one: that on hot days there are more enticing activities happening outside, providing a clear incentive to wrap up the business short and, for example, go grill some cheese.

…which brings another point: total length of speeches has not been analyzed. The parliamentary business is not uniform throughout the year, and I’d be absolutely not surprised to find that politicians reach their maximum levels of eloquence when divvying up the loot budget, which happens in late autumn in most countries – while the business discussed in summer is relatively less serious.

Lastly, we should not outright dismiss the possibility that heat is reminding politicians they’re all going to hell some day, thus scaring the [squeak] out of them.

1. Irony intended.