You'll remember from Daniel Pink's Drive (episode 2) that common assumptions about how rewards affect motivation and behaviour have it all wrong. Common sense tells us that to motivate somebody to do a better job, we should offer them a material reward, but scientific experiments show us that this is one of the best ways to demotivate people.

Perhaps you weren't so easily convinced. Well, good news! Alfie Kohn has written a book which argues in the finest detail and with the most colossal empirical support that rewards are bad for you and for everyone else. Starting off with an argument from principle, that there's something sinister and potentially immoral about offering rewards in the first place, he continues with a book-length exposition of all the terrible things that rewards can do, according to experimental psychology.

Why should you care? Because, if you're a teacher giving out grades for assignments, then the evidence strongly suggests that you are undermining your students' motivation. If you're a parent and you reward your child for studying, then you are reinforcing the idea that learning is a useless chore with no intrinsic benefits, done only for the goodie at the end. And if you offer praise when somebody does a good deed, scientific evidence shows that you are making them less ethical and less likely to do a good deed in the future in the absence of an external reward.

The really great thing about Alfie Kohn is his reliance on evidence as opposed to common sense or rhetoric to get his points across. Although he does use the latter where appropriate, it is clear throughout all of his books, no less this one, that his conclusions are well-supported by scientific enquiry. This book is a shining example of well-grounded argumentation (and of myth-busting). At the risk of not sounding impartial anymore, I'm willing to say that, as far as his approach to evidence is concerned, I personally consider Alfie Kohn to be a kind of professional role model.

So much is said in this book, that I can barely even attempt to fit it into a blog post. I've had to split up the episode into two parts to fit it all in. I hope this week's episode leaves you hungry for more.

Enjoy the episode.

#DeAcáEnMás - Massa le pagará al FMI con un crédito que recibirá hoy: Editorial de María O'Donnell