> "Our findings suggest that socioeconomic disparities in cognitive development start early," says Tucker-Drob. "For children from poorer homes, genetic influences on changes in cognitive ability were close to zero. For children from wealthier homes, genes accounted for about half of the variation in cognitive changes."
Another way to look at it is to say that, in a perfectly nurturing environment, everyone would achieve to the very peak of their genetic potential, and then genes would account for all of the variation in cognitive changes. So what deficits are there in the rich kids' environments that only half, rather than all, of the variation is genetic?
I suspect that the average "rich" environment is lacking plenty of things that a perfectly nurturing environment would have.
If you look at this through the lens of Maslow's hierarchy, a kid growing up in a poor environment is going to lack the fundamentals needed for cognitive development. He may be undernourished, for example. His guardians are probably too busy trying to make ends meet to read to him. They may even actively ignore him. He's handicapped right out of the starting gate and will likely never have a chance to reach his genetic potential.
In contrast, a child growing up in a rich family will have access to plenty of material goods. He's not going to worry about having to move 4 times in a year because his parents keep getting evicted. He's going to get sent to the best preschool money can buy. However, money can't buy him the drive to succeed on his own - to self-actualize, if you will. He's grown up in an environment where everything has been provided and nothing intrinsic to that environment is going to push him. He'll get closer to his genetic potential than the poor kid, but unless someone actively encourages him to develop his own potential, he's not going to get all the way, and there's your gap.
His guardians are probably too busy trying to make ends meet to read to him.
They certainly have time to read to him. The average person earning < $500/week has 32 minutes/day more leisure than a person earning at least $1181/week. They just choose to spend it on other things.
The average person earning < $500/week spends only 8 minutes/weekday reading (10 minutes on the weekend). In contrast, they spend 2 hours 15 minutes/weekday watching TV (3 hours 15 minutes on the weekend). That's 45 min/day more than the richer person.
I suspect a big component of why the poor children don't develop as much is because they observe their parents spending 2-3 hours/day watching TV, 8-10 minutes reading, and emulate those habits. (It's probably closer to 4 hours/day for the 80% of the poor who are not employed.)
The rich people observe their parents spending 15-30 minutes/day reading, less TV, more sports, and emulate those habits as well.
A scary thought: most people spend more than 2 hours/day watching TV. Imagine what might happen if everyone in America turned the TV off for an hour and did something productive!
Judging from the general numbers of successful individuals having been nurtured in "rich" environments (e.g. you'll find _much_ more kids going on to college in suburban schools than in inner-city schools), I would guess that either 1) the importance of success and the things that are required to achieve that success are clear to them - and so, they're better set to make wise, informed decisions, or 2) they've already gotten into a good work ethic - and if you're there, then it's easy - you largely have it made.
Because some of it will be based on random effects from the world around you, from unexpected things in your diet, from culture, from the TV, books, etc. you are exposed to, and many, many other things.
We don't generally set out to raise super-intelligent people pushed to fulfil every last drop of their potential.
And generally speaking, I'm fairly sure that's a good thing.
Because "fulfilling your potential" isn't necessarily the same as "being happy" (although achievement is one of the components of long-term happiness, according to my understanding). Focussing too much on any single aspect of your life will leave it out of balance and unhealthy.
Neglect. Their parents work all the time so they hire nannies and the sort to take care of them so they can spend the day bringing in the money. Then they develop drug addictions to prescription meds and "rich" drugs like cocaine. I mean there was also that Lifetime story of some woman who lived in foster homes her whole life, was homeless at one point, and got into Harvard. Unfortunately people will read this and go "that's what's wrong with me/my kids!" and use it as a cop-out.
Urgh, headline sucks! Does the study really find that being poor causes a limiting of mental ability? Or does being poor correlate with a limiting of mental ability?
My take is that bad nurturing causes the decline in mental ability, and wealth is merely a reasonable indicator for quality of nurturing. This distinction is important if attempts are made to mitigate the limitations.
I imagine a big effect on a child's cognitive development comes from the amount of time they spend with their parent. If wealthier families have fewer children, and therefore have more parental attention per child, that could explain the disparity.
I'm surprised at how these mindless studies keep on finding that if you don't eat well when you're a child, your brain won't have enough resources to fully develop. I thought we knew this from a long time ago.
How 'bout they do a study of how to feed the poor instead?
Ramanujan[1] had smallpox as a child and died due to malnutrition at the age of 32. As much as we would love to believe otherwise, intelligence is a genetic trait much like athleticism. Unfortunately, the former statement is taboo in our PC culture, while the latter is common sense.
Another way to look at it is to say that, in a perfectly nurturing environment, everyone would achieve to the very peak of their genetic potential, and then genes would account for all of the variation in cognitive changes. So what deficits are there in the rich kids' environments that only half, rather than all, of the variation is genetic?