Tim Spector, Professor of Twin Research and Genetic Epidemiology at King’s College, London, and author of Identically Different: Why You CAN Change Your Genes, tells us about just one of the surprising implications of his research for the way we live our lives – and the effects we might have already passed on to our unborn grandchildren.


At a talk I gave last week at the Cheltenham Science Festival about my new book, Identically Different, I was amazed by the breadth and quality of the questions. I had been speaking about how obesity in the current generation could be related to the early life stresses and famines experienced by our grandparents, which effectively ‘switched off’ certain genes in their offspring and in their children’s offspring, in a process known as epigenetics.

One member of the audience asked, ‘As a newgrandparent, what can I do to help my grandchildren epigenetically?’

I told him about the research that shows that mothers who stroke and show affection to their babies can alter their genes and even the genes of their unborn grandchildren. Cold mothers who deny their children cuddles have the opposite effect on their genes. But if children brought up by cold mothers are transferred at a young age to surrogate mothers who show tenderness towards them the effects on the genes can be reversed – and these changes can last several generations. So, to use the now redundant terms of the old debate: ‘nurture’ can effectively alter what we thought of as ‘nature’ – our genes. These studies have so far only taken place with rats, but the evidence suggests that the same effect occurs in humans.
Clearly, it wouldn’t be possible to perform the same experiments with humans, but if you look at the small group of unhappy families that have a cycle of failed parenting, delinquency and abuse, it is easy to detect a pattern. The bad habits of parents are repeated in their children, who themselves become poor parents, lacking empathy and the ability to give and read emotion and to support their children. Partly this is due to their gene variants they inherit; partly it is due to the environment of poverty and poor education in which most failed families find themselves; but, to a large extent, it is also likely to be due to a lack of early bonding which alters children’s genes for the worse, making them even more anxious and less empathetic with their peers and their children.
The British government recently announced that more was to be spent on the estimated 150,000 most dysfunctional British families who cost the taxpayer an incredible £9 billion annually. Breaking this cycle of poor parenting, abuse and delinquency is possible if we accept that ‘bad genes’ can be modified – and earlier use of adoption and surrogate parenting – before patterns get set for life.
So the short answer to the new grandfather trying to do the right thing for his grandchild is, yes, you can help your young grandchildren by cuddling them, and offering them security and protection. These good, protective effects could do more than set an example, they could have biological effects that will last them their lifetime and be transferred to their children and their children. Studies in rodents have shown that cuddled animals have less anxiety and stress, more empathy and show alterations in their stress hormones such as cortisol.
Of course, not all children react the same way. In my book I describe the Romanian orphans who were horribly abused for years, yet one in three of them remained, amazingly, unharmed by the experience a decade later. Some of us have in-built protective defence mechanisms that scientists don’t yet understand, and presumably genes which are less epigenetically malleable.
Yet, for most of us, the message to parents and grandparents is to carry on kissing and cuddling…