If the smell of woodsmoke makes you uneasy, it could be because your grandparents were once caught up in a house fire. That is the startling proposition thrown up by a study on mice, which indicates that fear can travel down the generations. For the research, a group of mice were taught to fear the smell of cherry blossoms by giving them mild foot shocks whenever they were exposed to it. These mice then bred. The resulting pups grew to adulthood without smelling cherry blossom – but the first time they caught a whiff of it, they showed clear signs of fear and unease. They also had more neurons of the type that detects the smell of cherry blossom. These mice then reproduced, and the same effect was seen in their offspring. The study, published in the journal Nature Neuroscience, adds to growing evidence suggesting that characteristics outside the strict genetic code may be acquired from our parents through epigenetic inheritance. Epigenetics is the study of changes in genetic activity not caused by changes in the DNA sequence. It was once thought that these changes could not be inherited, but there is a growing body of evidence that in fact, they create a lasting imprint. (Nature Neuroscience).

This finally explains why I cannot stand tapioca. Several ancestors had to breakfast on the stuff during their formative years.

Seriously, according to my accupuncturist, Jewish people have have a different pulse rhythm to other people, which is ascribed to constant bouts of fear and terror at the onset of pogroms. We are thus influenced, without knowing it, by the experiences of our ancestors, although no one is, I think, suggesting that social attitudes and politics are inherited st this point.

What has this to do with Epicurus? Nothing whatsoever – it is another piece of the jigsaw that explains human behavior and, as such, should lead us to be more understanding and tolerant about the curious behavior of people we encounter.