Sin – it’s good for you!

According to Simon Laham, a psychologist at the University of Melbourne and author of a new book, The Joy of Sin, Gregory need not have bothered. Because it turns out those sins are actually useful, even good for you.

This lighthearted but still serious book explains how pride, greed, sloth, gluttony, lust, envy and anger have developed over time and are often adaptive and useful.

While accepting that each of the deadly sins does have its downsides, Dr Laham points out that each also has “a range of positive, useful effects” that illustrate the complexity of human social and emotional behaviour.

And so we are led through a discussion of each sin in turn, finding that gluttony, for instance, is “adaptive in environments in which calories are scarce (like the African savannahs of our deep evolutionary history) but not in those in which calories are plentiful (like Mississippi)”.

(Mississippi, incidentally, doesn’t come out well in the book. Dr Laham cites a study by geographer Thomas Vought who sought to examine the American ‘sinscape’ by identifying the worst states for each of the sins. Mississippi carries off the triple title of most gluttonous, most lustful and most envious, although Louisiana is pretty bad too, being most angry and most proud.)

The reader learns that slothful daydreaming can be beneficial by turning our thoughts from routine activities toward things that are important to us in our future and which may need our attention; or that greed, if it doesn’t get out of hand and make us “unhelpful and sabotage our motives”, can make us “happier, more motivated, and self-sufficient”.

What is most wonderful about The Joy of Sin, however, is the insight it gives to the ways and means of experimental psychologists, of which Dr Laham is one, who devise ingenious and sometimes devious tests for their hapless subjects in order to collect data to prove or disprove their theorems.

Some of them are highly amusing, such as the experiment in which researchers studying gluttony, or at least over-eating, found that people will eat more when served more. To do this they brought a number of participants into a ‘laboratory setting’, supposedly to taste-test a new kind of tomato soup. Pots of it were rigged up to automatically and undetectably refill the bowls of a lucky – and presumably very full – few, who just kept on plugging away at the soup.

Or take the participants in an experiment on anger who role-play being mobile phone salespeople and who are confronted with happy, neutral or angry ‘customers’. In fact the customers are computers, and the ‘angry computer’ wins every time, driving down the price of the phone, subduing the seller, and proving the point that anger can work to the advantage of the enraged.

“This happens because anger expressions signal competence, ambition, and toughness, all factors that suggest that a negotiator knows what he’s doing and might be a fierce competitor”, he writes.

The Joy of Sin is witty and thought-provoking, an enjoyable glimpse into the world of experimental social and evolutionary psychology and a salve to the conscience of anyone raised in the shadow of Gregory’s harsh morality.

Simon Laham, The Joy of Sin. Constable and Robinson, 2012.