Most of us live lives confident in our ability to control our destiny through decisions freely arrived at, but increasing evidence points the die of our futures being cast from a very early age.
Just as teachers of very young children will say they can tell which of their pupils will prosper in later life and which might fall by the wayside, researchers are emphatic now about the influence of a baby’s time in the womb and those first years of life on its future prospects.
In the UK, scientists have been studying birth cohorts – large numbers of people born around the same period – since 1946 so their work now covers the arc of life from birth, through childhood, adolescence, adulthood and on into retirement.
So detailed is this information that researchers can confidently make predictions about a wide variety of life outcomes, from the age of menopause to later life mobility or the likelihood of suffering abuse.
In Ireland since 2007, close to 20,000 children are being tracked as part of the Growing Up in Ireland study, while 8,000 people aged over 50 are being followed in the Tilda study.
The first results of this Irish research, which are now becoming available, provide a fascinating glimpse into the powerful impact of early circumstances on later life events.
Early life environment
The findings tend to confirm international evidence that children's early life environments determine not only their physical health but also affect educational performance, involvement in crime, family breakdown and mental health, according to Prof Richard Layte of the Economic and Social Research Institute (ESRI).
Because outcomes vary so much across different income backgrounds, the findings have huge implications for Government policy.
But the overriding message is clear: it is far more effective to target the causes of health and social problems early on than to deal with the messy and expensive consequences later on.
Layte quotes approvingly the advice in a UK report to its government: “If people keep falling off a cliff, don’t worry about where you put the ambulance at the bottom. Build a fence at the top and stop them falling off in the first place.”
He says child risk factors cluster around socio-economic status, to the detriment of poorer children.
At the earliest stage, pre-natal smoking by mothers, low birth weight and low levels of breastfeeding combine to give some children the worst of starts.
Throw maternal depression and poor parenting behaviour into the mix and the child involved is already at a severe disadvantage.
The Irish data shows that birth weight declines in line with family income. Yet at age three, the risk of obesity is 75 per cent higher for children in the bottom half of the population by income. Children in the bottom fifth are 230 per cent more likely to be obese.
Mental health
Similar patterns have been identified for mental health, with a child's psychological wellbeing worse at lower income levels. The risk of serious emotional and behavioural problems at age nine is twice as high in the bottom half of income distribution.
Health problems persist into later life, the data shows; the risk of cardiovascular disease in later life is over a fifth higher among people who grew up in poor households.
The Tilda study, which looks at older people, is delivering similar results from a different angle. It shows that people who suffered early life adversity go on to have more physical and mental health problems.
Children who were abused were over 30 per cent more likely to suffer heart disease as adults for example. They were also over three times more likely to have psychiatric problems.
Even when the data was adjusted for factors such as age, gender, smoking and drinking, the trends were unchanged.
“A riskier early childhood environment is associated with earlier onset of disease,” says Dr Cathal McCrory of TCD, who has analysed the Tilda data.
Mild adversity
While scientists focus on the effect of early adversity on people's lives, they aren't unanimous in judging it to be negative. A minority view holds that mild adversity can be character-forming on the basis that "that which does not kill me make me stronger".
The data certainly reveal alarmingly high levels of adverse experience. Almost 15 per cent of children experienced the divorce or separation of their parents, and over 12 per cent witnessed conflict between parents, according to the Growing Up in Ireland research.
Layte points out that these figures would actually have been higher a few decades ago, when there was wider acceptance and incidence of abuse.
McCrory also cautions against the inevitable focus on the negative, and on problem areas. “The vast majority of children, and the vast majority of children growing up poor, are doing really well,” he points out.
