WHAT MAKES PEOPLE HAPPY?
You probably know the type: those Pollyannas who seem to have a relentlessly sunny disposition. Are they simply born happy? Is it the product of their environment? Or does it come from their life decisions?
If you are familiar with genetics research, you will have guessed that it is a combination of all three. A 2018 study of 1516 Norwegian twins suggests that around 30 per cent of the variance in people’s life satisfaction is inherited. Much of this seems to be related to personality traits, such as neuroticism, which can leave people more vulnerable to anxiety and depression, and extraversion, which encourages more gregarious behaviour. Both traits are known to be influenced by a range of genes.
To put this in context, the heritability of IQ is thought to hover around 80 per cent, so environmental factors clearly play a role in our happiness. These include our physical health, the size and strength of our social network, job opportunities and income. The effect of income, in particular, is nuanced: it seems that the absolute value of our salary matters less than whether we feel richer than those around us, which may explain why the level of inequality predicts happiness better than GDP.
Interestingly, many important life choices have only a fleeting influence on our happiness. Consider marriage. A 2019 study found that, on average, life satisfaction does rise after the wedding, but the feeling of married bliss tends to fade over middle age. Needless to say, this depends on the quality of the relationship: marriage’s impact on well-being is about twice as large …