Poverty can influence toddlers right down to their genes. That’s according to a study of 750 sets of twins, published this week in the journal Psychological Science. Assistant Professor Elliot Tucker-Drob of UT-Austin, who led the study, found that growing up poor can suppress a child’s potential to demonstrate his or her smarts. This can happen even before the age of two, Dr. Tucker-Drob discovered.
According to a press release from UT-Austin, it’s important to note that this study doesn’t suggest that children from more privileged backgrounds are genetically superior or smarter – it’s just that they have more opportunities to reach their intellectual potential. And, somehow, those opportunities allow for a greater expression of genetic gifts – the sort of thing we think of as innate talent. Tucker-Drob said;
You can’t have environmental contributions to a child’s development without genetics. And you can’t have genetic contributions without environment. Socioeconomic disadvantages suppress children’s genetic potentials.
Here’s how the study went. Dr. Tucker-Drob – who is also a research associate in UT’s Population Research Center – and his team looked at test results from twins who had taken a version of the Bayley Scales of Infant Development at about 10 months and again at about two years of age.
The Bayley test seems to hold water. It’s used frequently to measure early cognitive ability. The test requires kids to perform tasks like ringing a bell, matching pictures, and putting cubes in a cup. The study found that, at 10 months, all the kids – both these from economically advantaged and disadvantaged backgrounds – did similarly on the test. In other words, their economic status wasn’t affecting their cognitive skills. But something started to change around the age of two.
By two years, children from high socioeconomic background scored significantly higher than those from low socioeconomic backgrounds. In general, the two-year-olds from poorer families performed very similarly to one another. That was true among both fraternal and identical twins, suggesting that genetic similarity was unrelated to similarities in cognitive ability. Instead, their environments determine their cognitive success.
Among two-year-olds from wealthier families, identical twins (who share identical genetic makeups) performed very similarly to one another. But fraternal twins were not as similar — suggesting their different genetic makeups and potentials were already driving their cognitive abilities.
This study goes right to the heart of that age old “nature versus nurture” question. The results suggest that nurture, as time goes on, allows genes – smarts genes – to blossom.
And lack of nurture – which is, in this particular case, is not lack of caring or love, but lack of access to educational opportunities – allows genes to lie fallow.
If we think about the big picture here, the implications are huge. Over a billion people live in poverty. Meaning that the world, by allowing poverty to go on, not only keeps people from developing their gifts. Its deprives us of the opportunity to benefit from genius, because it’s lying dormant.
The researchers involved in this study note that “wealthier parents are often able to provide better educational resources and spend more time with their children, but [the study] does not examine what factors, in particular, help their children reach their genetic potentials.” They’re trying to figure out those factors in follow-up research.
Beth Lebwohl researches, writes and helps produce science content in audio and video formats for EarthSky. She is one of the authors on EarthSky.org, a script-writer for our podcasts, and helps host our English science podcasts in 90-second, 8-minute and 22-minute formats. Beth came to EarthSky in 2006 from the American Museum of Natural History's Department of Astrophysics, where she was surrounded by some of the greatest telescope-building, equation-wielding, code-writing physicists of our time. And they made her think . . . this science thing . . . it's pretty cool.