JEREMY LAURANCE FRIDAY 01 JUNE 2012
A combination of genes and our environment makes us what we are. Or so we always thought…
It is a shibboleth of family life – that every individual is the product of their genes and environment, the one an immutable inheritance, the other a mutable array of influences and pressures with unpredictable outcomes.
But new research has demonstrated that genes can change, identical twins with the same genetic inheritance can turn out completely different and the impact of environmental influences can be passed down the generations.
The new science of epigenetics has shown that in addition to nature and nurture, what makes us who we are is also determined by biological mechanisms that can switch genes on or off.
These epigenetic (above the gene) “light switches” can affect characteristics as fundamental as autism and sexual orientation.
But they are also subject to environmental influences and thus, in theory, are within our control.
Professor Tim Spector, head of the department of twin research at Kings College, London, who has undertaken the most detailed twin studies in the world, cited the case of Iranian twins Ladan and Laleh, who were joined at the head and shared identical genes and environment and yet had different personalities. The differences led him to question the influence of genes.