Psychologist Ulric Neisser, who, during 1995, headed an American Psychological Association task force writing a consensus statement on the state of intelligence research, estimates that if American children of 1932 could take an IQ test normed during 1997 their average IQ would have been only about 80
Considering Ravens, Neisser estimates that if he extrapolates beyond the data, which shows a 21-point gain between 1952 and 1982, an even larger gain of 35 IQ points can be argued.
For example, Dutch conscripts gained 21 points during only 30 years, or 7 points per decade, between 1952 and 1982.
In the United States
4.5 million children 5-17 years of age have ever been diagnosed with ADHD as of 2006. [Read article Adobe PDF file]
3%-7% of school-aged children suffer from ADHD. Some studies have estimated higher rates in community samples.1
7.8% of school-aged children were reported to have an ADHD diagnosis by their parent in 2003. [Read article]
Diagnosis of ADHD increased an average of 3% per year from 1997 to 2006. [Read article Adobe PDF file]
Boys (9.5%) are more likely than girls (5.9%) to have been diagnosed with ADHD. [Read article Adobe PDF file]
ADHD diagnosis is significantly higher among non-Hispanic, primarily English-speaking, and insured children. [Read article]
Prevalence rates are significantly higher for children in families in which the most highly educated adult was a high school graduate (or had completed 12 years of education), compared with children in families in which the most highly educated adult had a higher or lower level of education. [Read article]
ADHD diagnosis among males was reported significantly more often in families with incomes below the poverty threshold (<100%) than in families with incomes at or above the poverty threshold. Rates of reported diagnosis among females were not significantly different across the three levels of poverty. [Read article]
Prevalence varies substantially by state, from a low of 5% in Colorado to a high of 11.1% in Alabama. [Read article]
Diagnosed cases of attention deficit hyperactivity disorder increased almost 4 percent every year from 2000 to 2010 making it the number one mental health concern in children.
Boys are twice as likely to be diagnosed as girls. This is down dramatically from the 10 to 1 ratio in 1997.
In America, the state with highest number of cases reported was Alabama with the highest number of prescriptions being written in Arkansas.
Slightly less than 5.5 million children ranging in age from 5 to 17 were diagnosed with ADHD in 2009.
Currently 60 percent of all children with ADHD are receiving medication for treating the disorder, with Ritalin continuing to be the most widely prescribed.
The most highly medicated age demographic for ADHD children are those from 9 to 12 years of age.
Children with ADHD, compared to children with ADHD, were more likely to have major injuries (59% to 49%), hospital inpatient (26% to 18%), hospitalized outpatient (41% to 33%), or emergency room visits (81% to 74%).