IN YOUR GENES

The surprising things we inherit. This week: A fear of spiders

IT USED to be thought that our fears and phobias are down to how we’re brought up — for example, if your mother screamed when she saw a spider, you learned to do the same.

But in 2013, scientists at Emory University in the U.S. discovered fear of unpleasant experiences such as spiders can be passed down through generations by DNA.

Some unfortunate mice were trained to fear the smell of cherry blossom by associating it with a mild electric shock.

Tests on the mice’s offspring revealed they had a more fearful response to cherry blossom than a neutral odour, despite never encountering either smell before. The same was true for the next generation of mice. Even offspring conceived by artificial insemination and fostered by different animals were still scared of the smell, suggesting that fear can become imprinted on the gene. According to Gareth Evans, a professor of medical genetics and cancer epidemiology at the University of Manchester: ‘It’s feasible that findings such as inherited phobias in animal studies could lead to better diagnosis of psychiatric disorders and other forms of mental illness. ‘Even if we don’t establish the exact gene, we can appreciate a condition might affect the next generation.’